1ojp
|
SPECIFICITY AND MECHANISM OF STREPTOCOCCUS PNEUMONIAE HYALURONATE LYASE: COMPLEX WITH 6-SULPHATED CHONDROITIN DISACCHARIDE
OverviewOverview
Streptococcus pneumoniae hyaluronate lyase is a surface enzyme of this, Gram-positive bacterium. The enzyme degrades hyaluronan and, chondroitin/chondroitin sulfates by cleaving the beta1,4-glycosidic, linkage between the glycan units of these polymeric substrates. This, degradation helps spreading of this bacterial organism throughout the host, tissues and facilitates the disease process caused by pneumococci. The, mechanism of this degradative process is based on beta-elimination, is, termed proton acceptance and donation, and involves selected residues of a, well defined catalytic site of the enzyme. The degradation of hyaluronan, alone is thought to proceed through a processive mode of action. The, structures of complexes between the enzyme and chondroitin as well as, chondroitin sulfate disaccharides allowed for the first detailed insights, into these interactions and the mechanism of action on chondroitins. This, degradation of chondroitin/chondroitin sulfates is nonprocessive and is, selective for the chondroitin sulfates only with certain sulfation, patterns. Chondroitin sulfation at the 4-position on the nonreducing site, of the linkage to be cleaved or 2-sulfation prevent degradation due to, steric clashes with the enzyme. Evolutionary studies suggest that, hyaluronate lyases evolved from chondroitin lyases and still retained, chondroitin/chondroitin sulfate degradation abilities while being, specialized in the degradation of hyaluronan. The more efficient, processive degradation mechanism has come to be preferred for the, unsulfated substrate hyaluronan.
About this StructureAbout this Structure
1OJP 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
Structures of Streptococcus pneumoniae hyaluronate lyase in complex with chondroitin and chondroitin sulfate disaccharides. Insights into specificity and mechanism of action., Rigden DJ, Jedrzejas MJ, J Biol Chem. 2003 Dec 12;278(50):50596-606. Epub 2003 Sep 30. PMID:14523022
Page seeded by OCA on Tue Nov 20 22:58:43 2007