1egu
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CRYSTAL STRUCTURE OF STREPTOCOCCUS PNEUMONIAE HYALURONATE LYASE AT 1.56 A RESOLUTION
OverviewOverview
Streptococcus pneumoniae hyaluronate lyase (spnHL) is a pathogenic, bacterial spreading factor and cleaves hyaluronan, an important, constituent of the extra- cellular matrix of connective tissues, through, an enzymatic beta-elimination process, different from the hyaluronan, degradation by hydrolases in animals. The mechanism of hyaluronan binding, and degradation was proposed based on the 1.56 A resolution crystal, structure, substrate modeling and mutagenesis studies on spnHL. Five, mutants, R243V, N349A, H399A, Y408F and N580G, were constructed and their, activities confirmed our mechanism hypothesis. The important roles of, Tyr408, Asn349 and His399 in enzyme catalysis were proposed, explained and, confirmed by mutant studies. The remaining weak enzymatic activity of the, H399A mutant, the role of the free carboxylate group on the glucuronate, residue, the enzymatic behavior on chondroitin and chondroitin sulfate, and the small activity increase in the N580G mutant were explained based, on this mechanism. A possible function of the C-terminal beta-sheet domain, is to modulate enzyme activity through binding to calcium ions.
About this StructureAbout this Structure
1EGU is a Single protein structure of sequence from Streptococcus pneumoniae with SO4 as ligand. Active as Hyaluronate lyase, with EC number 4.2.2.1 Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of hyaluronan degradation by Streptococcus pneumoniae hyaluronate lyase., Li S, Kelly SJ, Lamani E, Ferraroni M, Jedrzejas MJ, EMBO J. 2000 Mar 15;19(6):1228-40. PMID:10716923
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