1ebb

From Proteopedia

BACILLUS STEAROTHERMOPHILUS YHFR

Overview

The crystal structure of Bacillus stearothermophilus PhoE (originally, termed YhfR), a broad specificity monomeric phosphatase with a molecular, mass of approximately 24 kDa, has been solved at 2.3 A resolution in order, to investigate its structure and function. PhoE, already identified as a, homolog of a cofactor-dependent phosphoglycerate mutase, shares with the, latter an alpha/beta/alpha sandwich structure spanning, as a structural, excursion, a smaller subdomain composed of two alpha-helices and one short, beta-strand. The active site contains residues from both the, alpha/beta/alpha sandwich and the sub-domain. With the exception of the, hydrophilic catalytic machinery conserved throughout the, cofactor-dependent phosphoglycerate mutase family, the active-site cleft, is strikingly hydrophobic. Docking studies with two diverse, favored, substrates show that 3-phosphoglycerate may bind to the catalytic core, while alpha-napthylphosphate binding also involves the hydrophobic portion, of the active-site cleft. Combining a highly favorable phospho group, binding site common to these substrate binding modes and data from related, enzymes, a catalytic mechanism can be proposed that involves formation of, a phosphohistidine intermediate on His10 and likely acid-base behavior of, Glu83. Other structural factors contributing to the broad substrate, specificity of PhoE can be identified. The dynamic independence of the, subdomain may enable the active-site cleft to accommodate substrates of, different sizes, although similar motions are present in simulations of, cofactor-dependent phosphoglycerate mutases, perhaps favoring a more, general functional role. A significant number of entries in protein, sequence databases, particularly from unfinished microbial genomes, are, more similar to PhoE than to cofactor-dependent phosphoglycerate mutases, or to fructose-2,6-bisphosphatases. This PhoE structure will therefore, serve as a valuable basis for inference of structural and functional, characteristics of these proteins.

About this Structure

1EBB is a Single protein structure of sequence from Geobacillus stearothermophilus with SO4 and GOL as ligands. Structure known Active Site: CAT. Full crystallographic information is available from OCA.

Reference

Structure and mechanism of action of a cofactor-dependent phosphoglycerate mutase homolog from Bacillus stearothermophilus with broad specificity phosphatase activity., Rigden DJ, Mello LV, Setlow P, Jedrzejas MJ, J Mol Biol. 2002 Feb 1;315(5):1129-43. PMID:11827481

Page seeded by OCA on Mon Nov 5 13:09:05 2007