Structural highlights
Function
[NUDD_ECOLI] Hydrolyzes both GDP-mannose and GDP-glucose. Could participate in the regulation of cell wall biosynthesis by influencing the concentration of GDP-mannose or GDP-glucose in the cell. Might also be involved in the biosynthesis of the slime polysaccharide colanic acid.[1] [2]
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 PubMed
GDP-mannose glycosyl hydrolase (GDPMH) catalyzes the hydrolysis of GDP-mannose and GDP-glucose to GDP and sugar by substitution with inversion at C1 of the sugar. The enzyme has a modified Nudix motif and requires one divalent cation for activity. The 1.3 A X-ray structure of the GDPMH-Mg(2+)-GDP complex, together with kinetic, mutational, and NMR data, suggests a mechanism for the GDPMH reaction. Several residues and the divalent cation strongly promote the departure of the GDP leaving group, supporting a dissociative mechanism. Comparison of the GDPMH structure with that of a typical Nudix hydrolase suggests how sequence changes result in the switch of catalytic activity from P-O bond cleavage to C-O bond cleavage. Changes in the Nudix motif result in loss of binding of at least one Mg(2+) ion, and shortening of a loop by 6 residues shifts the catalytic base by approximately 10 A.
Structure and mechanism of GDP-mannose glycosyl hydrolase, a Nudix enzyme that cleaves at carbon instead of phosphorus.,Gabelli SB, Bianchet MA, Azurmendi HF, Xia Z, Sarawat V, Mildvan AS, Amzel LM Structure. 2004 Jun;12(6):927-35. PMID:15274914[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Frick DN, Townsend BD, Bessman MJ. A novel GDP-mannose mannosyl hydrolase shares homology with the MutT family of enzymes. J Biol Chem. 1995 Oct 13;270(41):24086-91. PMID:7592609
- ↑ Legler PM, Massiah MA, Bessman MJ, Mildvan AS. GDP-mannose mannosyl hydrolase catalyzes nucleophilic substitution at carbon, unlike all other Nudix hydrolases. Biochemistry. 2000 Jul 25;39(29):8603-8. PMID:10913267
- ↑ Gabelli SB, Bianchet MA, Azurmendi HF, Xia Z, Sarawat V, Mildvan AS, Amzel LM. Structure and mechanism of GDP-mannose glycosyl hydrolase, a Nudix enzyme that cleaves at carbon instead of phosphorus. Structure. 2004 Jun;12(6):927-35. PMID:15274914 doi:10.1016/j.str.2004.03.028
