Linked Life Data

10779514

Source:http://linkedlifedata.com/resource/pubmed/id/10779514

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2000-8-10
pubmed:abstractText
A temperature-conditional, photosynthesis-deficient mutant of the green alga Chlamydomonas reinhardtii, previously recovered by genetic screening, results from a leucine 290 to phenylalanine (L290F) substitution in the chloroplast-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC ). Rubisco purified from mutant cells grown at 25 degrees C has a reduction in CO(2)/O(2) specificity and is inactivated at lower temperatures than those that inactivate the wild-type enzyme. Second-site alanine 222 to threonine (A222T) or valine 262 to leucine (V262L) substitutions were previously isolated via genetic selection for photosynthetic ability at the 35 degrees C restrictive temperature. These intragenic suppressors improve the CO(2)/O(2) specificity and thermal stability of L290F Rubisco in vivo and in vitro. In the present study, directed mutagenesis and chloroplast transformation were used to create the A222T and V262L substitutions in an otherwise wild-type enzyme. Although neither substitution improves the CO(2)/O(2) specificity above the wild-type value, both improve the thermal stability of wild-type Rubisco in vitro. Based on the x-ray crystal structure of spinach Rubisco, large subunit residues 222, 262, and 290 are far from the active site. They surround a loop of residues in the nuclear-encoded small subunit. Interactions at this subunit interface may substantially contribute to the thermal stability of the Rubisco holoenzyme.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19844-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Suppressor mutations in the chloroplast-encoded large subunit improve the thermal stability of wild-type ribulose-1,5-bisphosphate carboxylase/oxygenase.
pubmed:affiliation
Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't