Linked Life Data

1633805

Source:http://linkedlifedata.com/resource/pubmed/id/1633805

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-8-25
pubmed:abstractText
The 10 C-terminal residues are not visible in the crystal structure of lipoamide dehydrogenase from Azotobacter vinelandii, but can be observed in the crystal structures of the lipoamide dehydrogenases from Pseudomonas putida and Pseudomonas fluorescens. In these structures, the C-terminus folds back towards the active site and is involved in interactions with the other subunit. The function of the C-terminus of lipoamide dehydrogenase from A. vinelandii was studied by deletion of 5, 9 and 14 residues, respectively. Deletion of the last 5 residues does not influence the catalytic properties and conformational stability (thermoinactivation and unfolding by guanidinium hydrochloride). Removal of 9 residues results in an enzyme (enzyme delta 9) showing decreased conformational stability and high sensitivity toward inhibition by NADH. These features are even more pronounced after deletion of 14 residues (enzyme delta 14). In addition Tyr16, conserved in all lipoamide dehydrogenases sequenced thus far, and shown from the other structures to be likely to be involved in subunit interaction, was replaced by Phe and Ser. Mutation of Tyr16 also results in a strongly increased sensitivity toward inhibition by NADH. The conformational stability of both Tyr16-mutated enzymes is comparable to enzyme delta 9. The results strongly indicate that a hydrogen bridge between tyrosine of one subunit (Tyr16 in the A. vinelandii sequence) and histidine of the other subunit (His470 in the A. vinelandii sequence), exists in the A. vinelandii enzyme. In the delta 9 and delta 14 enzymes this interaction is abolished. It is concluded that this interaction mediates the redox properties of the FAD via the conformation of the C-terminus containing residues 450-470.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
207
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
499-505
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Lipoamide dehydrogenase from Azotobacter vinelandii. The role of the C-terminus in catalysis and dimer stabilization.
pubmed:affiliation
Department of Biochemistry, Agricultural University, Wageningen, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't