1y7o
From Proteopedia
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The structure of Streptococcus pneumoniae A153P ClpP
Overview
ClpP is a conserved serine-protease with two heptameric rings that enclose, a large chamber containing the protease active sites. Each ClpP subunit, can be divided into a handle region, which mediates ring-ring, interactions, and a head domain. ClpP associates with the hexameric, ATPases ClpX and ClpA, which can unfold and translocate substrate proteins, through the ClpP axial pores into the protease lumen for degradation. We, have determined the x-ray structure of Streptococcus pneumoniae, ClpP(A153P) at 2.5 A resolution. The structure revealed two novel features, of ClpP which are essential for ClpXP and ClpAP functional activities., First, the Ala --> Pro mutation disrupts the handle region, resulting in, an altered ring-ring dimerization interface, which, in conjunction with, biochemical data, demonstrates the unusual plasticity of this region., Second, the structure shows the existence of a flexible N-terminal loop in, each ClpP subunit. The loops line the axial pores in the ClpP tetradecamer, and then protrude from the protease apical surface. The sequence of the, N-terminal loop is highly conserved in ClpP across all kingdoms of life., These loops are essential determinants for complex formation between ClpP, and ClpX/ClpA. Mutation of several amino acid residues in this loop or the, truncation of the loop impairs ClpXP and ClpAP complex formation and, prevents the coupling between ClpX/ClpA and ClpP activities.
About this Structure
1Y7O is a Single protein structure of sequence from Streptococcus pneumoniae with CA as ligand. Active as Endopeptidase Clp, with EC number 3.4.21.92 Full crystallographic information is available from OCA.
Reference
The ClpP double ring tetradecameric protease exhibits plastic ring-ring interactions, and the N termini of its subunits form flexible loops that are essential for ClpXP and ClpAP complex formation., Gribun A, Kimber MS, Ching R, Sprangers R, Fiebig KM, Houry WA, J Biol Chem. 2005 Apr 22;280(16):16185-96. Epub 2005 Feb 8. PMID:15701650
Page seeded by OCA on Wed Nov 21 06:37:21 2007
