ISSN:
1573-4919
Keywords:
tyrosine kinase
;
v-Src
;
SH2 domain
;
SH3 domain
;
protein folding
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract To examine the interactions between Src homology,domains and the tyrosine kinase catalytic domain of v-Src, various combinations of domains have been expressed in bacteria as fusion proteins. Constructs containing the isolated catalytic domain, SH2 + catalytic domain, and SH3 + SH2 + catalytic domains were active in autophosphorylation assays. For the catalytic domain of v-Src, but not for v-Abl, addition of exogenous Src SH3-SH2 domains stimulated the autophosphorylation activity. In contrast to results for autophosphorylation, constructs containing Src homology domains were more active towards a synthetic peptide substrate than the isolated catalytic domain. The ability of the SH2 and SH3 domains of v-Src to stabilize an active enzyme conformation was also confirmed by refolding after denaturation in guanidinium hydrochloride. Collectively the data suggest that, in addition to their roles in intermolecular protein-protein interactions, the Src homology regions of v-Src exert a positive influence on tyrosine kinase function, potentially by maintaining an active conformation of the catalytic domain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00225883
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