Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-4-22
pubmed:abstractText
Isoleucine-164 is in Van der Waals contact with two ligands (lysine-191 and aspartate-193) of the activator magnesium ion at the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum. To observe the effect of mutations in the second sphere of coordination of the metal ion, isoleucine-164 was replaced by threonine, asparagine, and aspartate. All the mutant enzymes obtained exhibit a low carboxylase activity. Ile164Asp has less than 0.1% of the wild-type carboxylase activity, Ile164Thr and Ile164Asn 6 and 1%, respectively. The mutations increase the Km(RuBP) and decrease the Kcat of the mutated enzymes. The Kcat/Km(RuBP) of Ile164Thr and Ile164Asn are 40- and 900-fold lower than wild-type, respectively. The alteration of the hydrophobic contacts between isoleucine-164 and the metal ion ligands modifies the binding of the magnesium ion and the stabilization of the 2-carboxy-arabinitol 1,5-bisphosphate and decreases the specificity factor, tau.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
17
pubmed:volume
232
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
482-6
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Role of isoleucine-164 at the active site of rubisco from Rhodospirillum rubrum.
pubmed:affiliation
Genencor International, South San Francisco, California 94127, USA.
pubmed:publicationType
Journal Article