1usl

From Proteopedia

Revision as of 08:04, 3 February 2008

STRUCTURE OF MYCOBACTERIUM TUBERCULOSIS RIBOSE-5-PHOSPHATE ISOMERASE, RPIB, RV2465C, COMPLEXED WITH PHOSPHATE.

Overview

Ribose-5-phosphate isomerases (EC 5.3.1.6) inter-convert, ribose-5-phosphate and ribulose-5-phosphate. This reaction allows the, synthesis of ribose from other sugars, as well a means for salvage of, carbohydrates after nucleotide breakdown. Two unrelated types of enzyme, are known to catalyze the isomerization. The most common one, RpiA, is, present in almost all organisms. The second type, RpiB, is found in many, bacterial species.Here, we demonstrate that the RpiB from Mycobacterium, tuberculosis (Rv2465c) has catalytic properties very similar to those, previously reported for the Escherichia coli RpiB enzyme. Further, we, report the structure of the mycobacterial enzyme, solved by molecular, replacement and refined to 1.88A resolution. Comparison with the E.coli, structure shows that there are important differences in the two active, sites, including a change in the position and nature of the catalytic, base. Sequence comparisons reveal that the M.tuberculosis and E.coli RpiB, enzymes are in fact representative of two distinct sub-families. The, mycobacterial enzyme represents a type found only in actinobacteria, while, the enzyme from E.coli is typical of that seen in many other bacterial, proteomes. Both RpiBs are very different from RpiA in structure as well as, in the construction of the active site. Docking studies allow additional, insights into the reactions of all three enzymes, and show that many, features of the mechanism are preserved despite the different catalytic, components.

About this Structure

1USL is a Single protein structure of sequence from Mycobacterium tuberculosis with as ligand. Active as Ribose-5-phosphate isomerase, with EC number 5.3.1.6 Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Mycobacterium tuberculosis ribose-5-phosphate isomerase has a known fold, but a novel active site., Roos AK, Andersson CE, Bergfors T, Jacobsson M, Karlen A, Unge T, Jones TA, Mowbray SL, J Mol Biol. 2004 Jan 16;335(3):799-809. PMID:14687575

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