2jtc
3D structure and backbone dynamics of SPE B
Structural highlights
FunctionSPEB_STRP1 Important streptococcal virulence factor which cleaves human fibronectin and degrades vitronectin. Also cleaves human IL1B precursor to form biologically active IL1B. Can induce apoptosis in human monocytes and epithelial cells in vitro, and reduces phagocytic activity in monocytic cells. Thus, may play a role in bacterial colonization, invasion, and inhibition of wound healing.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedStreptococcal pyrogenic exotoxin B (SPE B) is a cysteine protease expressed by Streptococcus pyogenes. The D9N, G163S, G163S/A172S, and G239D mutant proteins were expressed to study the effect of the allelic variants on their protease activity. In contrast to other mutants, the G239D mutant was approximately 12-fold less active. The Gly-239 residue is located within the C-terminal S230-G239 region, which cannot be observed in the x-ray structure. The three-dimensional structure and backbone dynamics of the 28-kDa mature SPE B (mSPE B) were determined. Unlike the x-ray structure of the 40-kDa zymogen SPE B (proSPE B), we observed the interactions between the C-terminal loop and the active site residues in mSPE B. The structural differences between mSPE B and proSPE B were the conformation of the C-terminal loop and the orientation of the catalytic His-195 residue, suggesting that activation and inactivation of SPE B is involved in the His-195 side-chain rotation. Dynamics analysis of mSPE B and the mSPE B/inhibitor complexes showed that the catalytic and C-terminal loops were the most flexible regions with low order parameter values of 0.5 to 0.8 and exhibited the motion on the ps/ns timescale. These findings suggest that the flexible C-terminal loop of SPE B may play an important role in controlling the substrate binding, resulting in its broad substrate specificity. Solution structure and backbone dynamics of streptopain: insight into diverse substrate specificity.,Wang CC, Houng HC, Chen CL, Wang PJ, Kuo CF, Lin YS, Wu JJ, Lin MT, Liu CC, Huang W, Chuang WJ J Biol Chem. 2009 Apr 17;284(16):10957-67. Epub 2009 Feb 23. PMID:19237546[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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