2gkd
From Proteopedia
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Structural insight into self-sacrifice mechanism of enediyne resistance
Overview
The recent discovery of the first "self-sacrifice" mechanism for bacterial, resistance to the enediyne antitumor antibiotics, where enediyne-induced, proteolysis of the resistance protein CalC inactivates both the highly, reactive metabolite and the resistance protein, revealed yet another, ingenious bacterial mechanism for controlling reactive metabolites. As, reported herein, the first 3D structures of CalC and CalC in complex with, calicheamicin (CLM) divulge CalC to be a member of the steroidogenic acute, regulatory protein (StAR)-related transfer (START) domain superfamily. In, contrast to previous studies of proteins known to bind DNA-damaging, natural products ( e.g ., bleomycins, mitomycins, and nine-membered, chromoprotein enediynes), this is the first demonstrated involvement of a, START domain fold. Consistent with the CalC self-sacrifice mechanism, CLM, in complex with CalC is positioned for direct hydrogen abstraction from, Gly113 to initiate the oxidative proteolysis-based resistance mechanism., These structural studies also illuminate, for the first time, a small, DNA-binding region within CalC that may serve to localize CalC to the, enediyne target (DNA). Given the role of START domains in, nuclear/cytosolic transport and translocation, this structural study also, may implicate START domains as post-endocytotic intracellular chaperones, for enediyne-based therapeutics such as MyloTarg.
About this Structure
2GKD is a Single protein structure of sequence from Micromonospora echinospora. Full crystallographic information is available from OCA.
Reference
Structural insight into the self-sacrifice mechanism of enediyne resistance., Singh S, Hager MH, Zhang C, Griffith BR, Lee MS, Hallenga K, Markley JL, Thorson JS, ACS Chem Biol. 2006 Aug 22;1(7):451-60. PMID:17168523
Page seeded by OCA on Tue Jan 29 20:01:48 2008
