Acta Crystallographica Section D
Biological
Crystallography
ISSN0907-4449
Notes for authors2003
1.Scientific scope
Section D of Acta Crystallographica welcomes the submission of papers covering any aspect of structural biology,particularly structures of biological macromolecules.In addition to new structural determinations, preliminary data on unit-cell dimensions and space groups will be considered for publication,provided suitable diffraction photographs(or their equivalent),together with an estimate of resolution,are included. Also,articles on crystal growth of biological macromolecules are welcomed,and re®ne-ments of known structures may be published if the information content warrants it.For all structural papers,suf®cient evidence should be provided to convince the referees that the interpretations of the diffraction data and electron-density maps are correct,within the resolution of the analysis.
2.Categories of contributions Contributions should conform to the general editorial style of the journal.
2.1.Research Papers
Full-length Research Papers should not normally exceed15journal pages(about 15000words).
2.2.Short Communications
Short Communications are intended for the presentation of topics of limited scope, or for preliminary announcements of novel research®ndings.They are not intended for interim reports of work in progress,and must report results that are of scienti®c value in their own right.
Short Communications should not exceed two journal pages(about1500words).A maximum of two®gures and two tables of appropriate size are permitted.
2.3.Crystallization Papers
These are short papers which report the crystallization of novel,important or dif®cult-to-crystallize biological macro-molecules,or new crystallization techniques. In general,a submission will only be considered if the structure of the macro-molecule has not been published already.
Crystallization Papers should not
normally exceed two journal pages(about
1500words).Authors should take into
account the evaluation criteria given in x11.
Crystallization Papers should be
submitted to one of the Crystallization
Co-editors,whose addresses appear on the
inside front cover of each issue.
2.4.Structural Genomics Papers
This category of papers provides rapid
reporting of structural genomics research.
Full details can be found at journals.
2.5.Lead Articles
Lead Articles are authoritative,compre-
hensive and forward-looking reviews of
major areas of research interest.They are
always commissioned by the Section Editors,
on the advice of the Editorial Board.
Suggestions for suitable topics and of
editor assigned后editor invitedpotential author(s)are welcomed by the
Section Editors for discussion with the
Board.
The Section Editors will discuss the
treatment of the topic,the length of the
Article and the delivery date of the manu-
script with invited author(s);Lead Articles
will be refereed in the normal manner.
2.6.Topical Reviews
A Topical Review is a short,highly
focused survey covering a relatively narrow
area of current research interest.It should
not aim to be comprehensive,but a brief
introduction should provide historical
perspective and a brief conclusion should
indicate likely future directions.
Topical Reviews will be limited to about
ten journal pages(10000words)except
in special agreed circumstances.Shorter
reviews on rapidly evolving areas are also
actively encouraged.They will be commis-
sioned by the Section Editors either
personally,or following a formal proposal by
prospective author(s).Topical Reviews will
be refereed in the normal way.
2.7.Letters to the Editor
These may deal with non-technical
aspects of crystallography,its role,its
propagation,the proper function of its
Societies etc.,or may make a technical
observation that would usefully be brought
to a wider audience.Letters should be
submitted to one of the Section Editors or to
the Editor-in-chief of Acta Crystallographica
only.
2.8.Scientific Comment
Comments of general scienti®c interest to
the readership are welcomed.These should
not normally exceed two journal pages and
should be submitted as in x3.
2.9.Meeting Reports
These are normally invited.Prospective
authors interested in writing such items
should®rst contact the Section Editors.
2.10.New Commercial Products
Announcements of new commercial
products are published free of charge.The
descriptions,up to300words or the
equivalent if a®gure is included,should give
the manufacturer's full address.
2.11.Obituaries
These will be commissioned by the
Section Editors.
3.Submission and handling of
manuscripts
Papers should be submitted in one of two
ways:as hard copy directly to a Co-editor
or Section Editor or electronically via
the web at /services/
submit.html.
3.1.Hard-copy submission
Manuscripts and®gures should be
prepared using the®le formats listed in x3.9.
Three paper copies and the electronic®le(s)
should be submitted;authors are reminded
to keep an exact copy of the submission for
later editorial adjustments and for checking
proofs.Unless stated otherwise in x2,the
submission should be sent to a Section
Editor or any of the Co-editors taking into
account their areas of expertise.On accep-
tance,an electronic version of the®nal
manuscript will be required by the Editorial Of®ce.
Contact details for the editors are avail-able at /d/services/ editors.html.
3.2.Electronic submission Manuscripts and®gures should be prepared using the®le formats listed in x3.9. Full details of the submission procedure can be found at /services/ submit.html and authors should®rst check this page to see if the service is available.
3.3.Languages of publication
Acta Crystallographica Section D will publish papers in English,French,German and Russian.
3.4.Handling of manuscripts
All contributions will be seen by referees (normally two)before they can be accepted for publication.The editor to whom the manuscript is assigned is responsible for choosing referees and for accepting or rejecting the paper.This responsibility includes decisions on the®nal form of the paper and interpretation of these Notes when necessary.
If changes to a manuscript requested by a Section Editor,Co-editor or the editorial staff are not received within two months of transmittal to the author,the submission will automatically be withdrawn.Should the manuscript require further revision,this would normally be expected to be completed within one month of the revision having been requested.Any subsequent communication of the material will be treated as a new submission in the editorial process.
For accepted papers,it is the responsi-bility of the Managing Editor to prepare the paper for printing.This may involve corre-spondence with the authors and/or the responsible editor in order to resolve ambi-guities or to obtain satisfactory®gures or tables.The date of acceptance that will appear on the published paper is the date on which the Managing Editor receives the last item required.Correspondence will be sent to the author who submitted the paper unless the Managing Editor is informed of some other suitable arrangement.
On rare occasions an editor may consider that a paper is better suited to a section of Acta Crystallographica other than that speci®ed by the author(s),to the Journal of Applied Crystallography or to the Journal of Synchrotron Radiation.Any change to the section or journal of publication will only be
made after full discussion with the commu-
nicating author.
3.5.Author's warranty
The submission of a paper is taken as an
implicit guarantee that the work is original,
that it is the author(s)own work,that all
authors concur with and are aware of the
submission,that all workers involved in the
study are listed as authors or given proper
credit in the acknowledgements,that the
manuscript has not already been published
(in any language or medium),and that it is
not being considered and will not be offered
elsewhere while under consideration for an
IUCr journal.The inclusion of material in an
informal a preprint server
or a newsletter,does not preclude publica-
tion in an IUCr journal.All authors will be
required to sign off the®nal version of the
paper.
Important considerations related to
publication have been given in the ethical
guidelines published in Acc.Chem.Res.
(2002),35,74±76.
3.6.Copyright
Except as required otherwise by national
laws,an author must sign and submit a copy
of the Transfer of Copyright Agreement
form for each manuscript before it can be
accepted.During the electronic submission
process,authors will be asked to transfer
copyright electronically.
3.7.Author grievance procedure
An author who believes that a paper has
been unjusti®ably treated by the Co-editor
may appeal initially to a Section Editor and
then to the Editor-in-chief if still aggrieved
by the decision.
3.8.Contact e-mail address
The contact author must provide an
e-mail address for editorial communications
and despatch of electronic proofs.
3.9.File format
The manuscript should be prepared using
T E X,L A T E X or Word.Authors are encour-
aged to use the templates available from the
Editorial Of®ce by e-mail()or
by ftp(from the`templates'directory).All
Word submissions should be accompanied
by an RTF(rich text format)®le.
Figures may be provided in PostScript,
encapsulated PostScript or TIFF formats.
The resolution of bitmap graphics should be
a minimum of600d.p.i.
3.10.File transfer
For electronic submissions the®les
should be uploaded via the web.Full details
of this procedure are given at
/services/submit.html.
For hard-copy submissions®nal electronic
®les must have a®lename constructed from
the reference number supplied by the Co-
editor.Files should be given the extensions
Ftex,Fdo and Frtf as appropriate.Illus-
trations should be given the extensions Fps,
Feps or Ftif.Multiple®les for the same
submission should be uniquely identi®ed
xzIHVUFdo ,etc.where xz1087is the refer-
ence number.
Only after acceptance of the paper by the
responsible editor should the®nal electronic
version of the paper be sent to the Editorial
Of®ce in Chester.This may be via the web
(see above),by e-mail(),on
diskette or by ftp as described below.
4.Abstract and synopsis
All contributions must be accompanied by
an English language Abstract and a one or
two sentence Synopsis of the main®ndings
of the paper for inclusion in the Table of
Contents for the relevant issue.The Abstract
should state as speci®cally and as quantita-
tively as possible the principal results
obtained.
The Abstract should be suitable for
reproduction by abstracting services without
change in wording.It should not repeat
information given in the title.Ordinarily200
words suf®ce for Abstracts of Research
Papers,Lead Articles and Topical Reviews,
and100words for shorter contributions.It
should make no reference to tables,
diagrams,atom numbers or formulae
contained in the paper.It should not contain
footnotes.Numerical information given in
the Abstract should not be repeated in the
text.It should not include the use of`we'
or`I'.
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(iv)Wait for ftpb prompt
and enter:
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(v)Transfer a®le from your
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put jPWFps
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(vii)Finish off the ftp session
by entering: ye
(viii)Send an e-mail to Chester(meddiu rForg)
with a list of the®les transferred by ftp
Literature references in an Abstract are discouraged.If a reference is unavoidable,it should be suf®ciently full within the Abstract for unambiguous identi®[Terwil-liger(1994).Acta Cryst.D50,17±23].
5.Diagrams and photographs
(`figures')
Figures should be prepared using one of the ®le formats listed in x3.9.
The choice of tables and®gures should be optimized to produce the shortest printed paper consistent with clarity.Duplicate presentation of the same information in both tables and®gures is to be avoided,as is redundancy with the text.
Authors of protein structure papers are requested to submit a picture of the C chain trace.This will be helpful for referees and may be deposited.In addition,a diagram of the®t of a side chain is helpful to the reader in terms of assessing the resolu-tion and map quality.
Fibre data should contain appropriate information such as a photograph of the data.As primary diffraction data cannot be satisfactorily extracted from such®gures,the basic digital diffraction data should be deposited.
5.1.Quality
Electronic®les in the formats listed in x3.9 are essential for high-quality reproduction. The resolution of bitmap graphics should be a minimum of600d.p.i.Where electronic ®les are not available,hard-copy greyscale or colour images should be provided as glossy prints.Laser printer or photocopier output will generally be unsatisfactory for reproduction of such diagrams.
5.2.Size
Diagrams should be as small as possible consistent with legibility.They will normally be sized so that the greatest width including lettering is less than the width of a column in the journal.
5.3.Lettering and symbols
Fine-scale details and lettering must be large enough to be clearly legible(ideally 1.5±3mm in height)after the whole diagram has been reduced to one column width. Lettering should be kept to a m
inimum; descriptive matter should be placed in the legend.5.4.Numbering and legends
Diagrams should be numbered in a single
series in the order in which they are referred
to in the text.A list of the legends(`®gure
captions')should be included in the manu-
script.
5.5.Stereofigures
Atom labelling when included should be
on both left and right views in stereo
perspective.Both views should be incorp-
orated into a single®gure.
5.6.Colour figures
Figures in colour are accepted at no cost
to the author provided that the editor agrees
that they improve the understanding of the
paper.At the editor's discretion,®gures
printed in black and white may appear in
colour in Crystallography Journals Online.
6.Tables
Authors submitting in Word should use the
Word table editor to prepare tables.
6.1.Use of tables
Extensive numerical information is
generally most economically presented in
tables.Text and diagrams should not be
redundant with the tables.
6.2.Design,numbering and size
Tables should be numbered in a single
series of arabic numerals in the order in
which they are referred to in the text.They
should be provided with a caption.
Tables should be carefully designed to
occupy a minimum of space consistent with
clarity.
7.Mathematics and letter symbols
Authors submitting in Word should use the
Word equation editor to prepare displayed
mathematical equations.
The use of the stop(period)to denote
multiplication should be avoided except in
scalar products.Generally no sign is
required but,when one is,a multiplication
sign(Â)should be used.
Vectors should be in bold type and tensors
should be in bold-italic type.
Greek letters should not be spelled out.
Care should be taken not to cause
confusion by using the same letter symbol in
two different meanings.
Gothic,script or other unusual lettering
should be avoided.Another typeface may be
substituted if that used by the author is not
readily available.
Equations,including those in published
Appendices,should be numbered in a single
series.
8.Multimedia
Multimedia additions to a ime-
lapse sequences,three-dimensional struc-
tures)are welcomed;they will be made
available via Crystallography Journals
Online.
9.Nomenclature
9.1.Crystallographic nomenclature
Authors should follow the general
recommendations produced by the IUCr
Commision on Crystallographic Nomen-
clature(see reports at /
iucr-top/comm/cnom/).
Atoms of the same chemical species
within an asymmetric unit should be distin-
guished by an appended arabic numeral.
Chemical and crystallographic numbering
should be in agreement wherever possible.
When it is necessary to distinguish crystal-
lographically equivalent atoms in different
asymmetric units the distinction should be
made by lower-case roman numeral super-
i,ii,iii etc.)to the original atom
labels.
Space groups should be designated by the
Hermann±Mauguin symbols.Standard cell
settings,as listed in Volume A of Interna-
tional Tables for Crystallography,should be
used unless objective reasons to the contrary
are stated.When a non-standard setting is
used,the list of equivalent positions should
be given.Hermann±Mauguin symbols
should also be used for designating point
groups and molecular symmetry.It is helpful
if the origin used is stated explicitly where
there is a choice.
The choice of axes should normally follow
the recommendations of the Commission on
Crystallographic Data[Kennard et al.
(1967).Acta Cryst.22,445±449].
A symbol such as123or hkl without
brackets is understood to be a re¯ection,
(123)or(hkl)a plane or set of planes,[123]
or[uvw]a direction,{hkl}a form and h uvw i
all crystallographically equivalent directions
of the type[uvw].Other bracket notations
should be explicitly de®ned.
9.2.Nomenclature of chemical compounds
etc.
Chemical formulae and nomenclature
should conform to the rules of nomenclature
established by the International Union of Pure and Applied Chemistry(IUPAC),the International Union of Biochemistry and Molecular Biology(IUBMB),the Interna-tional Mineralogical Association and other appropriate bodies.As far as possible the crystallographic nomenclature should correspond to the systematic name.
Any accepted trivial or non-systematic name may be retained,but the corre-sponding systematic(IUPAC)name should also be given.
9.3.Units
The International System of Units(SI)is used except that the aÊngstroÈm(symbol AÊ, de®ned as10À10m)is generally preferred to the nanometre(nm)or picometre(pm)as the appropriate unit of length.Recom-mended pre®xes of decimal multiples should be used rather than`Â10n'.
10.References
References to published work must be indicated by giving the authors'names followed immediately by the year of Neder&Schulz(1998)or(Neder &Schulz,1998).Where there are three or more authors the reference in the text should be indicated in the form Smith et al. (1998)or(Smith et al.,1998)etc.(all authors should be included in the full list).
In the reference list,entries for journals [abbreviated in the style of Chemical Abstracts(the abbreviations Acta Cryst.,J. Appl.Cryst.and J.Synchrotron Rad.are exceptions)],books,multi-author books, computer programs,personal communica-tions and undated documents should be arranged alphabetically and conform with the following style:
BruÈnger,A.T.(1992a).X-PLOR.Version3.1.A System for X-ray Crystallography and NMR. Yale University,Connecticut,USA.
BruÈnger,A.T.(1992b).Nature(London),355, 472±474.
Collaborative Computational Project,Number4 (1994).Acta Cryst.D50,760±763. Crowther,R.A.(1972).The Molecular Replace-ment Method,edited by M.G.Rossmann,pp. 173±178.New York:Gordon and Breach. International Union of Crystallography(1999). (IUCr)Crystallography Journals Online,
International Union of Crystallography(2001). (IUCr)Structure Reports Online, /e/journalhomepage.html. Sheldrick,G.M.(2003).Acta Cryst.D59.In the press.
Yariv,J.(1983).Personal communication.
Note that inclusive page numbers must be
given.
Identi®cation of individual structures in
the paper by use of database reference
(identi®cation)codes should be accom-
panied by a full citation of the original
literature in the reference list.However,in
tables containing more than ten such refer-
ence codes,citation in the reference list is
not required.
11.Evaluation criteria
The information required in manuscripts is
given below.
11.1.Crystallization data
A list of data recommended for inclusion
in Crystallization Papers can be found on
the web at /d/services/
crystallization/.
11.2.Resolution
The effective resolution should be
described clearly.Values of the internal
agreement of the data,R merge,together with
the he average number of
measurements for each re¯ection from
which R merge is calculated),the percentage
of data with I>3'(I)and percentage
completeness of the data are required for
the overall data set and the highest resolu-
tion shell together with the limits of that
shell in AÊ.For high-quality data obtained
with synchrotron radiation,values of
R merge<20%,completeness>93%and
observable data>70%should be achievable
for the highest resolution shell.A complete
table listing the above criteria as a function
of resolution should also be submitted,but
will normally be included in the supple-
mentary material,see x13.
11.3.Unrefined structures
Adequate experimental details should be
provided to convince referees that the
interpretation is correct,within the resolu-
tion of the analysis.If heavy-atom deriva-
tives were used,suf®cient data should be
provided for evaluation of the quality of
those derivatives.The®t of the model to the
electron-density maps used to determine the
structure should be shown or described by
quantitative indicators,such as real-space
residuals.
11.4.Refined structures
For re®ned structures the data required
depend on the effective resolution of the
analysis.The following should be included.
A®nal Ramachandran plot is important
and should be provided for review purposes.
The paper should include a brief statement
of the percentage of amino acids in allowed,
additionally allowed and disallowed regions
of the plot.
s.deviations in B values within
each residue's main-chain and side-chain
atoms should be included.
The crystallographic R index should be
tabulated as a function of resolution and
R free should also be included.
Adequate details should be provided
regarding the steps followed in constructing
the model and re®ning the structure.Also
requested are:the number of solvent atoms;
solvent B values;the history and salient
details of the re®nement methods employed,
including the resolution ranges that were
used at various stages of re®nement;the
restraints used;a description of how the
thermal parameters were treated;and how
the solvent sites were selected and handled
during re®nement.It should be clear if van
der Waals distances were restrained.
Hydrogen-bonding patterns within the
protein should be described including the
number of hydrogen-bond donors not
involved in hydrogen bonding and any
unsatis®ed buried main-chain hydrogen
bonds.
Any structural features that are consid-
ered somewhat unusual should be described.
Examples include cis peptide bonds;unoc-
cupied volume inside the protein,buried
charge groups that are not involved in salt
bridges or reasonable hydrogen-bonding
environments;unusual locations of glycine
and proline residues;unusual distributions
of polar and hydrophobic groups within the
molecule;and unusual bond lengths,bond
angles,planes,intra-and intermolecular
contacts.
12.Small-molecule structure
determinations
Papers that report the results of crystal
structure determinations of small molecules
must report the associated experimental
data as required in Notes for Authors for
Section C of Acta Crystallographica.These
data should be supplied as a single electronic
®le in CIF format.The CIF will be checked
in Chester for internal consistency.
13.Supplementary publication
procedure(deposition)
13.1.Purpose and scope
Parts of some papers are of interest to
only a small number of readers,and the cost
of printing these parts is not warranted. Arrangements have therefore been made for such material to b
e made available from the IUCr electronic archive via Crystallography Journals Online or to be deposited with the Protein Data Bank,the Nucleic Acid Database and the ICDD as appropriate.
13.2.IUCr electronic archive
All material for deposition in the IUCr electronic archive should be supplied elec-tronically.
Non-structural information,which may include:
details of the experimental procedure; details of the stages of structure re®nement; details of mathematical derivations given only in outline in the main text and in mathematical Appendices;
lengthy discussion of points that are not of general interest or that do not lead to de®nite conclusions but that do have signi®cant value; and additional diagrams,
should be supplied in one of the formats given in x3.9.
Structural information(for small-mole-cule structures)should be supplied in CIF format;structure factors should be supplied as.fcf®les.13.3.Macromolecular structures
Authors should follow the deposition
recommendations of the IUCr Commission
on Biological Macromolecules[Acta Cryst.
(2000),D56,2].For all structural studies of
macromolecules,coordinates and structure
factors must be deposited with the Protein
Data Bank or the Nucleic Acid Database if a
total molecular structure has been reported.
Authors must supply the Protein Data Bank/
Nucleic Acid Database reference codes
before the paper can be published.
13.4.Crystallization data
For Crystallization Papers,authors are
recommended to deposit their data with the
relevant database.
14.Powder diffraction data
Authors of powder diffraction papers should
consult the notes provided at the online CIF
help page(/c/services/
cifhelp.html).For papers that present the
results of powder diffraction pro®le®tting or
re®nement(Rietveld)methods,the primary
diffraction he numerical intensity
of each measured point on the pro®le as a
function of scattering angle,will be depos-
ited.
15.Crystallography Journals Online
All IUCr journals are available on the
web via Crystallography Journals Online;
/.Full details of
author services can be found at
/d/services/authorservices.
html.
15.1.Electronic status information
Authors may obtain information about
the current status of their papers at
/services/status.html.
15.2.Proofs
Proofs will be provided in portable
document format(pdf).The correspondence
author will be noti®ed by e-mail when the
proofs are ready for downloading.
15.3.Reprints
After publication,the correspondence
author will be able to download the elec-
tronic reprint of the published article,free of
charge.Authors will also be able to order
printed reprints at the proof stage.