1F7B

CRYSTAL STRUCTURE ANALYSIS OF N-ACETYLNEURAMINATE LYASE FROM HAEMOPHILUS INFLUENZAE: CRYSTAL FORM II IN COMPLEX WITH 4-OXO-SIALIC ACID

Summary for 1F7B

• Entry DOI: 10.2210/pdb1f7b/pdb
• Related: 1F5Z 1F6K 1F73 1FDY 1FDZ 1NAL
• Descriptor: N-ACETYL-NEURAMINATE LYASE, 4,4,6,7,8,9-HEXAHYDROXY-5-METHYLCARBOXAMIDONONANOIC ACID, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: beta barrel, lyase
• Biological source: Haemophilus influenzae
• Cellular location: Cytoplasm: P44539
• Total number of polymer chains: 2
• Total formula weight: 65763.15

Authors

Barbosa, J.A.R.G.,Smith, B.J.,DeGori, R.,Lawrence, M.C. (deposition date: 2000-06-26, release date: 2000-11-22, Last modification date: 2024-11-06)

Primary citation

Barbosa, J.A.R.G.,Smith, B.J.,DeGori, R.,Ooi, H.C.,Marcuccio, S.M.,Campi, E.M.,Jackson, W.R.,Brossmer, R.,Sommer, M.,Lawrence, M.C.
Active site modulation in the N-acetylneuraminate lyase sub-family as revealed by the structure of the inhibitor-complexed Haemophilus influenzae enzyme.
J.Mol.Biol., 303:405-421, 2000

PubMed Abstract: The N-acetylneuraminate lyase (NAL) sub-family of (beta/alpha)(8) enzymes share a common catalytic step but catalyse reactions in different biological pathways. Known examples include NAL, dihydrodipicolinate synthetase (DHDPS), d-5-keto-4-deoxyglucarate dehydratase, 2-keto-3-deoxygluconate aldolase, trans-o-hydroxybenzylidenepyruvate hydrolase-aldolase and trans-2'-carboxybenzalpyruvate hydratase-aldolase. Little is known about the way in which the three-dimensional structure of the respective active sites are modulated across the sub-family to achieve cognate substrate recognition. We present here the structure of Haemophilus influenzae NAL determined by X-ray crystallography to a maximum resolution of 1.60 A, in native form and in complex with three substrate analogues (sialic acid alditol, 4-deoxy-sialic acid and 4-oxo-sialic acid). These structures reveal for the first time the mode of binding of the complete substrate in the NAL active site. On the basis of the above structures, that of substrate-complexed DHDPS and sequence comparison across the sub-family we are able to propose a unified model for active site modulation. The model is one of economy, allowing wherever appropriate the retention or relocation of residues associated with binding common substrate substituent groups. Our structures also suggest a role for the strictly conserved tyrosine residue found in all active sites of the sub-family, namely that it mediates proton abstraction by the alpha-keto acid carboxylate in a substrate-assisted catalytic reaction pathway.

PubMed: 11031117
DOI: 10.1006/jmbi.2000.4138

Experimental method

X-RAY DIFFRACTION (1.8 Å)