{{Short description|Dutch macromolecular computational program}} {{Infobox software | name = WHAT IF | logo = <!-- Image name is enough --> | logo alt = | screenshot = <!-- Image name is enough --> | caption = | screenshot alt = | collapsible = | author = Gert Vriend, Chris Sander, Wolfgang Kabsch | developer = <!--Chronological sort, earliest to latest.-->University of Groningen;<br />EMBL, Heidelberg;<br />CMBI, Radboud University Nijmegen;<br />Radboud University Nijmegen Medical Centre (Radboudumc)<br />WHAT IF Foundation | released = {{Start date and age|1987|12|06|df=yes}} | discontinued = | latest release version = 6.0 | latest release date = {{Start date and age|2016|df=yes}}<!-- Can someone knowledgeable add |MM|DD| ? --> | latest preview version = | latest preview date = <!-- {{Start date and age|YYYY|MM|DD|df=yes/no}} --> | programming language = Fortran, C, OpenGL | operating system = Linux | platform = x86 | size = | language = English | language count = <!-- Number only --> | language footnote = | genre = Molecular modelling | license = Proprietary, shareware for academics | alexa = | website = {{URL|https://swift.cmbi.umcn.nl/whatif/}} | standard = | AsOf = }}
'''WHAT IF''' is a computer program used in a wide variety of computational (''in silico'') macromolecular structure research fields. The software provides a flexible environment to display, manipulate, and analyze small and large molecules, proteins, nucleic acids, and their interactions.<ref name=home>{{cite web|title=WHAT IF homepage|url=https://swift.cmbi.umcn.nl/whatif/|accessdate=21 February 2022}}</ref><ref name=jmolgraph90>{{cite journal|last1=Vriend|first1=G|title=WHAT IF: a molecular modeling and drug design program.|journal=Journal of Molecular Graphics|date=March 1990|volume=8|issue=1|pages=52–6, 29|pmid=2268628|doi=10.1016/0263-7855(90)80070-v}}</ref>
==History== The first version of the WHAT IF software was developed by Gert Vriend in 1987 at the University of Groningen, Groningen, Netherlands.<ref name=jmolgraph90 /> Most of its development occurred during 1989–2000 at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany. Other contributors include Chris Sander, and Wolfgang Kabsch.<ref name=contributors>{{cite web|title=WHAT IF - Who are we|url=http://swift.cmbi.ru.nl/whatif/WIF1_2.html|accessdate=11 August 2015|archive-date=12 September 2015|archive-url=https://web.archive.org/web/20150912141905/http://swift.cmbi.ru.nl/whatif/WIF1_2.html|url-status=dead}}</ref> In 2000, maintenance of the software moved to the Dutch Center for Molecular and Biomolecular Informatics (CMBI) in Nijmegen, Netherlands.<ref name="home" /> It is available for in-house use, or as a web-based resource.<ref name=servers>{{cite journal|last1=Rodriguez|first1=R|last2=Chinea|first2=G|last3=Lopez|first3=N|last4=Pons|first4=T|last5=Vriend|first5=G|title=Homology modeling, model and software evaluation: three related resources.|journal=Bioinformatics|date=1998|volume=14|issue=6|pages=523–8|pmid=9694991|doi=10.1093/bioinformatics/14.6.523|doi-access=free}}</ref> {{As of|February 2022}}, the original paper describing WHAT IF has been cited more than 4,000 times.
==Software== WHAT IF provides a flexible environment to display, manipulate, and analyze small molecules, proteins, nucleic acids, and their interactions. One notable use was detecting many millions of errors (often small, but sometimes catastrophic) in Protein Data Bank (PDB) files.<ref name=pdb-errors>{{cite journal|last1=Hooft|first1=RW|last2=Vriend|first2=G|last3=Sander|first3=C|last4=Abola|first4=EE|title=Errors in protein structures.|journal=Nature|date=23 May 1996|volume=381|issue=6580|pages=272|pmid=8692262|doi=10.1038/381272a0| bibcode=1996Natur.381..272H | s2cid=4368507 |doi-access=free}}</ref> WHAT IF also provides an environment for: homology modeling of protein tertiary structures and quaternary structures; validating protein structures, notably those deposited in the PDB; correcting protein structures; visualising macromolecules and their interaction partners (for example, lipids, drugs, ions, and water), and manipulating macromolecules interactively.
WHAT IF is compatible with several other bioinformatics software packages, including YASARA and Jmol.<ref name=home />
==See also== * List of molecular graphics systems * Molecule editor
==External links== * {{Official website|https://swift.cmbi.umcn.nl/whatif/}}
==References== {{Reflist}}
Category:Molecular modelling software Category:Bioinformatics software Category:Protein structure