Cyrstal structure of Escherichia coli Glucose-1-Phosphate Thymidylyltransferase (RffH) complexed with dTTP and Mg2+

Download
  1. Get@NRC: Cyrstal structure of Escherichia coli Glucose-1-Phosphate Thymidylyltransferase (RffH) complexed with dTTP and Mg2+ (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1074/jbc.M206932200
AuthorSearch for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleThe Journal of Biological Chemistry
Volume277
Issue46
Pages4421444219; # of pages: 6
AbstractThe enzyme glucose-1-phosphate thymidylyltransferase (RffH), the product of therffh gene, catalyzes one of the steps in the synthesis of enterobacterial common antigen (ECA), a cell surface glycolipid found in Gram-negative enteric bacteria. InEscherichia coli two gene products, RffH and RmlA, catalyze the same enzymatic reaction and are homologous in sequence; however, they are part of different operons and function in different pathways. We report the crystal structure of RffH bound to deoxythymidine triphosphate (dTTP), the phosphate donor, and Mg2+, refined at 2.6 Å to an R-factor of 22.3% (R free = 28.4%). The crystal structure of RffH shows a tetrameric enzyme best described as a dimer of dimers. Each monomer has an overall α/β fold and consists of two domains, a larger nucleotide binding domain (residues 1–115, 222–291) and a smaller sugar-binding domain (116–221), with the active site located at the domain interface. The Mg2+ ion is coordinated by two conserved aspartates and the α-phosphate of deoxythymidine triphosphate. Its location corresponds well to that in a structurally similar domain of N-acetylglucosamine-1-phosphate uridylyltransferase (GlmU). Analysis of the RffH, RmlA, and GlmU complexes with substrates and products provides an explanation for their different affinities for Mg2+ and leads to a proposal for the dynamics along the reaction pathway.
Publication date
LanguageEnglish
AffiliationNRC Biotechnology Research Institute; National Research Council Canada
Peer reviewedNo
NRC number44874
NPARC number3538969
Export citationExport as RIS
Report a correctionReport a correction
Record identifier5041e28f-8a8d-4ccf-a27c-71d6fe84e47f
Record created2009-03-01
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)