'''Simple Modular Architecture Research Tool''' ('''SMART''') is a [[classificationbiological schemedatabase]] that is used in the identification and analysis of [[protein ___domain]]s within protein sequences.<ref name="pmid9600884">{{cite journal | author vauthors=Schultz J, Milpetz F, Bork P, Ponting CP | title = SMART, a simple modular architecture research tool: identification of signaling domains | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 95 | issue = 11 | pages = 5857–64 | year date=May 1998 | month = May | pmid = 9600884 | pmc = 34487 | doi = 10.1073/pnas.95.11.5857| bibcode = 1998PNAS...95.5857S | url = http://www.pnas.org/content/95/11/5857.full.pdf| issndoi-access = free }}</ref><ref name="pmid18978020">{{cite journal | author vauthors=Letunic I, Doerks T, Bork P | title = SMART 6: recent updates and new developments | journal = Nucleic Acids Res. | volume = 37 | issue = Database issue | pages = D229–32 | year date=January 2009 | month = January | pmid = 18978020 | pmc = 2686533 | doi = 10.1093/nar/gkn808 | url = | issn = }}</ref> SMART uses [[hidden Markov model|profile-hidden Markov models]] built from [[multiple sequence alignment]]s to detect protein domains in protein sequences. The most recent release of SMART contains 1,009204 ___domain models.<ref name="pmid22053084">{{citeCite journal|authorlast1=Letunic I, |first1=Ivica|last2=Doerks T, |first2=Tobias|last3=Bork|first3=Peer|date=January P 2015|title=SMART 7: recent updates, tonew thedevelopments proteinand ___domainstatus annotation resourcein 2015|journal=Nucleic Acids Res. Research|volume=40 43|issue=Database issue|pages=D302–5 |year=2012 |month=January |pmid=22053084 |pmc=3245027 D257–260|doi=10.1093/nar/gkr931 gku949|urlissn=1362-4962|pmc=4384020|pmid=25300481}}</ref> Data from SMART was used in creating the [[Conserved Domain Database]] collection and is also distributed as part of the [[InterPro]] database.<ref name="pmid12230031">{{cite journal |authorvauthors=Mulder NJ, Apweiler R, Attwood TK, ''et al.''etal |title=InterPro: an integrated documentation resource for protein families, domains and functional sites |journal=Brief. Bioinformatics |volume=3 |issue=3 |pages=225–35 |yeardate=September 2002 |month=September |pmid=12230031 |doi= 10.1093/bib/3.3.225|urldoi-access=free }}</ref> The database is hosted by the [[European Molecular Biology Laboratory]] in Heidelberg.