1mg9
From Proteopedia
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The structural basis of ClpS-mediated switch in ClpA substrate recognition
Overview
In Escherichia coli, protein degradation is performed by several, proteolytic machines, including ClpAP. Generally, the substrate, specificity of these machines is determined by chaperone components, such, as ClpA. In some cases, however, the specificity is modified by adaptor, proteins, such as ClpS. Here we report the 2.5 A resolution crystal, structure of ClpS in complex with the N-terminal domain of ClpA. Using, mutagenesis, we demonstrate that two contact residues (Glu79 and Lys 84), are essential not only for ClpAS complex formation but also for, ClpAPS-mediated substrate degradation. The corresponding residues are, absent in the chaperone ClpB, providing a structural rationale for the, unique specificity shown by ClpS despite the high overall similarity, between ClpA and ClpB. To determine the location of ClpS within the ClpA, hexamer, we modeled the N-terminal domain of ClpA onto a structurally, defined, homologous AAA+ protein. From this model, we proposed a molecular, mechanism to explain the ClpS-mediated switch in ClpA substrate, specificity.
About this Structure
1MG9 is a Protein complex structure of sequences from Escherichia coli with SPK as ligand. Full crystallographic information is available from OCA.
Reference
Structural analysis of the adaptor protein ClpS in complex with the N-terminal domain of ClpA., Zeth K, Ravelli RB, Paal K, Cusack S, Bukau B, Dougan DA, Nat Struct Biol. 2002 Dec;9(12):906-11. PMID:12426582
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