Editing SH3 domain (section)

{{short description|Small protein domain found in some kinases and GTPases}}
{{Infobox protein family
| Symbol = SH3_1
| Name = SH3 domain
| image =1shg SH3 domain.png
| width =200
| caption =[[Ribbon diagram]] of the SH3 domain, alpha spectrin, from [[chicken]] (PDB accession code 1SHG), colored from blue (N-terminus) to red (C-terminus).
| Pfam= PF00018
| Pfam_clan= CL0010
| ECOD = 4.1.1
| InterPro= IPR001452
| SMART=  SM00326
| PROSITE = PS50002
| SuperFamily = SSF50044
| SCOP = 1shf
| TCDB =
| CDD = cd00174
| OPM family=
| OPM protein=
| PDB=
}}

The '''SRC Homology 3 Domain'''  (or '''SH3 domain''')  is a small [[protein domain]] of about 60 [[amino acid]] residues. Initially, SH3 was described as a [[conserved sequence]] in the [[Virus|viral]] [[Signal transducing adaptor protein|adaptor protein]] v-Crk. This domain is also present in the molecules of phospholipase and several cytoplasmic [[tyrosine kinase]]s such as [[Abl gene|Abl]] and [[Sarcoma inducing gene|Src]].<ref name="pmid15335710">{{cite journal | vauthors = Pawson T, Schlessingert J | title = SH2 and SH3 domains | journal = Current Biology | volume = 3 | issue = 7 | pages = 434–42 | date = July 1993 | pmid = 15335710 | doi = 10.1016/0960-9822(93)90350-W | s2cid = 53273571 }}</ref><ref name="pmid11256992">{{cite journal | vauthors = Mayer BJ | title = SH3 domains: complexity in moderation | journal = Journal of Cell Science | volume = 114 | issue = Pt 7 | pages = 1253–63 | date = April 2001 | doi = 10.1242/jcs.114.7.1253 | pmid = 11256992 }}</ref> It has also been identified in several other protein families such as: [[PI3 Kinase]], [[Ras superfamily|Ras]] [[RasGAP|GTPase-activating protein]], [[CDC24]] and [[cdc25]].<ref name="pmid1639195">{{cite journal | vauthors = Musacchio A, Gibson T, Lehto VP, Saraste M | title = SH3--an abundant protein domain in search of a function | journal = FEBS Letters | volume = 307 | issue = 1 | pages = 55–61 | date = July 1992 | pmid = 1639195 | doi = 10.1016/0014-5793(92)80901-R | s2cid = 8564342 | doi-access =  }}</ref><ref name="pmid14731533">{{cite journal | vauthors = Mayer BJ, Baltimore D | title = Signalling through SH2 and SH3 domains | journal = Trends in Cell Biology | volume = 3 | issue = 1 | pages = 8–13 | date = January 1993 | pmid = 14731533 | doi = 10.1016/0962-8924(93)90194-6 }}</ref><ref name="pmid7531822">{{cite journal | vauthors = Pawson T | title = Protein modules and signalling networks | journal = Nature | volume = 373 | issue = 6515 | pages = 573–80 | date = February 1995 | pmid = 7531822 | doi = 10.1038/373573a0 | s2cid = 4324726 }}</ref> SH3 domains are found in proteins of signaling pathways regulating the [[cytoskeleton]], the [[Ras protein]], and the [[Src kinase]] and many others. The SH3 proteins interact with adaptor proteins and tyrosine kinases. Interacting with tyrosine kinases, SH3 proteins usually bind far away from the [[active site]]. Approximately 300 SH3 domains are found in proteins encoded in the human genome. In addition to that, the SH3 domain was responsible for controlling protein-protein interactions in the [[signal transduction pathways]]<ref>{{cite journal | vauthors = Schlessinger J | title = SH2/SH3 signaling proteins | journal = Current Opinion in Genetics & Development | volume = 4 | issue = 1 | pages = 25–30 | date = February 1994 | pmid = 8193536 | doi = 10.1016/0959-437X(94)90087-6 }}</ref> and regulating the interactions of proteins involved in the cytoplasmic signaling.<ref>{{cite journal | vauthors = Koch CA, Anderson D, Moran MF, Ellis C, Pawson T | title = SH2 and SH3 domains: elements that control interactions of cytoplasmic signaling proteins | journal = Science | volume = 252 | issue = 5006 | pages = 668–74 | date = May 1991 | doi = 10.1126/science.1708916 | pmid = 1708916 }}</ref>