Linked Life Data

11371194

Source:http://linkedlifedata.com/resource/pubmed/id/11371194

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2001-5-23
pubmed:databankReference
pubmed:abstractText
The crystal structures of 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDOPS) from Escherichia coli complexed with the substrate phosphoenolpyruvate (PEP) and with a mechanism-based inhibitor (K(d) = 0.4 microM) were determined by molecular replacement using X-ray diffraction data to 2.8 and 2.3 A resolution, respectively. Both the KDOPS.PEP and KDOPS.inhibitor complexes crystallize in the cubic space group I23 with cell constants a = b = c = 117.9 and 117.6 A, respectively, and one subunit per asymmetric unit. The two structures are nearly identical, and superposition of their Calpha atoms indicates an rms difference of 0.41 A. The PEP in the KDOPS.PEP complex is anchored to the enzyme in a conformation that blocks its si face and leaves its re face largely devoid of contacts. This results from KDOPS's selective choice of a PEP conformer in which the phosphate group of PEP is extended toward the si face. Furthermore, the structure reveals that the bridging (P-O-C) oxygen atom and the carboxylate group of PEP are not strongly hydrogen-bonded to the enzyme. The resulting high degree of negative charge on the carboxylate group of PEP would then suggest that the condensation step between PEP and D-arabinose-5-phosphate (A5P) should proceed in a stepwise fashion through the intermediacy of a transient oxocarbenium ion at C2 of PEP. The molecular structural results are discussed in light of the chemically similar but mechanistically distinct reaction that is catalyzed by the enzyme 3-deoxy-D-arabino-2-heptulosonate-7-phosphate synthase and in light of the preferred enzyme-bound states of the substrate A5P.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6326-34
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Crystal structures of KDOP synthase in its binary complexes with the substrate phosphoenolpyruvate and with a mechanism-based inhibitor.
pubmed:affiliation
Department of Chemistry, University of Houston, Houston, Texas 77204-5641, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't