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Titolo:
The crystal structure of yeast thiamin pyrophosphokinase
Autore:
Baker, LJ; Dorocke, JA; Harris, RA; Timm, DE;
Indirizzi:
Indiana Univ, Sch Med, Dept Biochem & Mol Biol, Indianapolis, IN 46202 USAIndiana Univ Indianapolis IN USA 46202 l Biol, Indianapolis, IN 46202 USA
Titolo Testata:
STRUCTURE
fascicolo: 6, volume: 9, anno: 2001,
pagine: 539 - 546
SICI:
0969-2126(200106)9:6<539:TCSOYT>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANGSTROM RESOLUTION; 6-HYDROXYMETHYL-7,8-DIHYDROPTERIN PYROPHOSPHOKINASE; SACCHAROMYCES-CEREVISIAE; PYRUVATE DECARBOXYLASE; BACILLUS-SUBTILIS; ESCHERICHIA-COLI; DIFFRACTION DATA; PROTEIN; DIPHOSPHATE; CRYSTALLOGRAPHY;
Keywords:
thiamin; pyrophosphokinase; X-ray crystallography; multiwavelength anomalous dispersion; metabolism;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Timm, DE Indiana Univ, Sch Med, Dept Biochem & Mol Biol, Indianapolis, IN 46202 USA Indiana Univ Indianapolis IN USA 46202 ndianapolis, IN 46202 USA
Citazione:
L.J. Baker et al., "The crystal structure of yeast thiamin pyrophosphokinase", STRUCTURE, 9(6), 2001, pp. 539-546

Abstract

Background: Thiamin pyrophosphokinase (TPK) catalyzes the transfer of a pyrophosphate group from ATP to vitamin B-1 (thiamin) to form the coenzyme thiamin pyrophosphate (TPP). Thus, TPK is important for the formation of a coenzyme required for central metabolic functions. TPK has no sequence homologs in the PDB and functions by an unknown mechanism. The TPK structure has been determined as a significant step toward elucidating its catalytic action. Results: The crystal structure of Saccharomyces cerevisiae TPK complexed with thiamin has been determined at 1.8 Angstrom resolution, TPK is a homodimer, and each subunit consists of two domains. One domain resembles a Rossman fold with four alpha helices on each side of a 6 strand parallel beta sheet. The other domain has one 4 strand and one 6 strand antiparallel beta sheet, which form a flattened sandwich structure containing a jelly-roll topology. The active site is located in a cleft at the dimer interface and is formed from residues from domains of both subunits. The TPK dimer contains two compound active sites at the subunit interface. Conclusions: The structure of TPK with one substrate bound identifies the location of the thiamin binding site and probable catalytic residues. The structure also suggests a likely binding site for ATP. These findings are further supported by TPK sequence homologies. Although possessing no significant sequence homology with other pyrophospokinases, thiamin pyrophosphokinase may operate by a mechanism of pyrophosphoryl transfer similar to those described for pyrophosphokinases functioning in nucleotide biosynthesis.

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Documento generato il 20/09/20 alle ore 06:01:32