1MRN

CRYSTAL STRUCTURE OF MYCOBACTERIUM TUBERCULOSIS THYMIDYLATE KINASE COMPLEXED WITH BISUBSTRATE INHIBITOR (TP5A)

Summary for 1MRN

• Entry DOI: 10.2210/pdb1mrn/pdb
• Related: 1G3U 1MRS
• Descriptor: Thymidylate Kinase, SULFATE ION, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: transferase (atp:tmp phosphotransferase), kinase, transferase
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 1
• Total formula weight: 23770.31

Authors

Haouz, A.,Vanheusden, V.,Munier-Lehmann, H.,Froeyen, M.,Herdewijn, P.,Van Calenbergh, S.,Delarue, M. (deposition date: 2002-09-18, release date: 2003-01-07, Last modification date: 2024-02-14)

Primary citation

Haouz, A.,Vanheusden, V.,Munier-Lehmann, H.,Froeyen, M.,Herdewijn, P.,Van Calenbergh, S.,Delarue, M.
Enzymatic and structural analysis of inhibitors designed against Mycobacterium tuberculosis thymidylate kinase. New insights into the phosphoryl transfer mechanism.
J.Biol.Chem., 278:4963-4971, 2003

PubMed Abstract: The chemical synthesis of new compounds designed as inhibitors of Mycobacterium tuberculosis TMP kinase (TMPK) is reported. The synthesis concerns TMP analogues modified at the 5-position of the thymine ring as well as a novel compound with a six-membered sugar ring. The binding properties of the analogues are compared with the known inhibitor azido-TMP, which is postulated here to work by excluding the TMP-bound Mg(2+) ion. The crystallographic structure of the complex of one of the compounds, 5-CH(2)OH-dUMP, with TMPK has been determined at 2.0 A. It reveals a major conformation for the hydroxyl group in contact with a water molecule and a minor conformation pointing toward Ser(99). Looking for a role for Ser(99), we have identified an unusual catalytic triad, or a proton wire, made of strictly conserved residues (including Glu(6), Ser(99), Arg(95), and Asp(9)) that probably serves to protonate the transferred PO(3) group. The crystallographic structure of the commercially available bisubstrate analogue P(1)-(adenosine-5')-P(5)-(thymidine-5')-pentaphosphate bound to TMPK is also reported at 2.45 A and reveals an alternative binding pocket for the adenine moiety of the molecule compared with what is observed either in the Escherichia coli or in the yeast enzyme structures. This alternative binding pocket opens a way for the design of a new family of specific inhibitors.

PubMed: 12454011
DOI: 10.1074/jbc.M209630200

Experimental method

X-RAY DIFFRACTION (2.45 Å)