SH3 domains are small, modular domains that are found in many proteins, especially signal transduction proteins such as tyrosine kinases. While much is known about the sequences and tertiary structures of SH3 domains, far less is known about their solution dynamics. A slow, partial unfolding event that occurs under physiological conditions was previously identified in the Hck SH3 domain using hydrogen exchange (HX) mass spectrometry (MS). To determine if this unfolding was unique to Hck SH3, HX MS was used to analyze 11 other SH3 domains: seven SH3 domains from Src-family kinases and five SH3 domains from various proteins. A wide variety of unfolding rates were found, with unfolding half-lives ranging from 1s to 1h. The Lyn and alpha-spectrin SH3 domains exhibited slow, partial unfolding in beta strands D and E and part of the RT-loop. Hck SH3 also underwent partial unfolding in the same region, implying that a unique feature in this area of the domains is responsible for the partial unfolding. Partial unfolding was, however, not a function of sequence conservation. Although the Fyn and Yes SH3 domains are very similar to Hck SH3 in sequence, they exhibited no evidence of partial unfolding. Overall, the results suggest that while the tertiary structure of SH3 domains is highly conserved, the dynamics of SH3 domains are variable. Study holds ProTherm entries: 22139, 22140, 22141 Extra Details: SH3 domain hydrogen exchange; mass spectrometry; protein dynamics; Src-family kinases
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:53 p.m.
|Number of data points||3|
|Proteins||Spectrin alpha chain, non-erythrocytic 1 ; Tyrosine-protein kinase HCK ; Spectrin alpha chain, non-erythrocytic 1 ; Tyrosine-protein kinase HCK ; Tyrosine-protein kinase Lyn ; SH3 DOMAIN OF HUMAN LYN TYROSINE KINASE|
|Assays/Quantities/Protocols||Experimental Assay: Tm|
|Libraries||Mutations for sequence GAMGSGIRIIVVALYDYEAIHHEDLSFQKGDQMVVLEESGEWWKARSLATRKEGYIPSNYVARVDSLETEEWFFKGISRKDAERQLLAPGNMLGSFMIRDSETTKGSYSLSVRDYDPRQGDTVKHYKIRTLDNGGFYISPRSTFSTLQELVDHYKKGNDGLCQKLSVPCMSSKPQKPWEKDAWEIPRESLKLEKKLGAGQFGEVWMATYNKHTKVAVKTMKPGSMSVEAFLAEANVMKTLQHDKLVKLHAVVTKEPIYIITEFMAKGSLLDFLKSDEGSKQPLPKLIDFSAQIAEGMAFIEQRNYIHRDLRAANILVSASLVCKIADFGLARVIEDNEYTAREGAKFPIKWTAPEAINFGSFTIKSDVWSFGILLMEIVTYGRIPYPGMSNPEVIRALERGYRMPRPENCPEELYNIMMRCWKNRPEERPTFEYIQSVLDDFYTATESQYEEIP ; Mutations for sequence MDETGKELVLALYDYQEKSPREVTMKKGDILTLLNSTNKDWWKVEVNDRQGFVPAAYVKKLD ; Mutations for sequence GSPEEQGDIVVALYPYDGIHPDDLSFKKGEKMKVLEEHGEWWKAKSLLTKKEGFIPSNYVAKLNT|