1dim
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SIALIDASE FROM SALMONELLA TYPHIMURIUM COMPLEXED WITH EPANA INHIBITOR
OverviewOverview
The structure of Salmonella typhimurium LT2 neuraminidase (STNA) is, reported here to a resolution of 1.6 angstroms together with the, structures of three complexes of STNA with different inhibitors. The first, is 2-deoxy-2,3-dehydro-N-acetyl-neuraminic acid (Neu5Ac2en or DANA), the, second and third are phosphonate derivatives of N-acetyl-neuraminic acid, (NANA) which have phosphonate groups at the C2 position equatorial (ePANA), and axial (aPANA) to the plane of the sugar ring. The complex structures, are at resolutions of 1.6 angstroms, 1.6 angstroms and 1.9 angstroms, respectively. These analyses show the STNA active site to be topologically, inflexible and the interactions to be dominated by the arginine triad, with the pyranose rings of the inhibitors undergoing distortion to occupy, the space available. Solvent structure differs only around the third, phosphonate oxygen, which attracts a potassium ion. The STNA structure is, topologically identical to the previously reported influenza virus, neuraminidase structures, although very different in detail; the, root-mean-square (r.m.s) deviation for 210 C alpha positions considered, equivalent is 2.28 angstroms (out of a total of 390 residues in influenza, and 381 in STNA). The active site residues are more highly conserved, in, that both the viral and bacterial structures contain an arginine triad, a, hydrophobic pocket, a tyrosine and glutamic acid residue at the base of, the site and a potential proton-donating aspartic acid. However, differences in binding to O4 and to the glycerol side-chain may reflect, the different kinetics employed by the two enzymes.
About this StructureAbout this Structure
1DIM is a Single protein structure of sequence from Salmonella typhimurium with K and EQP as ligands. Active as Exo-alpha-sialidase, with EC number 3.2.1.18 Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
The structures of Salmonella typhimurium LT2 neuraminidase and its complexes with three inhibitors at high resolution., Crennell SJ, Garman EF, Philippon C, Vasella A, Laver WG, Vimr ER, Taylor GL, J Mol Biol. 1996 Jun 7;259(2):264-80. PMID:8656428
Page seeded by OCA on Tue Dec 18 14:44:41 2007