Linked Life Data

9662562

Source:http://linkedlifedata.com/resource/pubmed/id/9662562

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-1-15
pubmed:abstractText
Three lines of evidence indicate that arginine-46 (R46) and arginine-275 (R275) are essential to the function of UhpT, the Pi-linked antiport protein of Escherichia coli. A role for arginine was initially suggested by the sensitivity of UhpT to inhibition by 2,3-butanedione, an arginine-directed probe. Since the presence of substrate protected against this inhibition, this work further suggested that arginine(s) may lie at or near the UhpT active site. In other work, each UhpT arginine was examined individually by using site-directed mutagenesis to generate a cysteine or a lysine derivative. With two exceptions (R46, R275), all arginines could be replaced by either cysteine (10 of 14 residues) or lysine (12 of 14) without loss of function, implicating R46 and R275 as essential to UhpT function. This idea was strengthened by examining a multiple alignment of the eleven known UhpT-related proteins (>/=30% identity). That alignment showed R46 and R275 were two of the only three arginines strongly conserved in this group of proteins. Considered together, these different approaches lead us to conclude that UhpT and its relatives have only two arginine residues (R46, R275) whose presence is essential to function. Prior biochemical work had placed R275 at the external entrance to the translocation pathway, and a symmetry argument emerging from the multiple alignment suggests a similar position for R46. Accordingly, by virtue of their locations at the entrance to this pathway, we speculate that R46 and R275 function in establishing substrate specificity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
164
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
187-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Identification of two essential arginine residues in UhpT, the sugar phosphate antiporter of Escherichia coli.
pubmed:affiliation
Department of Physiology, Johns Hopkins Medical School, Baltimore, MD, 21205 USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.