Linked Life Data

1730724

Source:http://linkedlifedata.com/resource/pubmed/id/1730724

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-2-18
pubmed:databankReference
pubmed:abstractText
A cDNA encoding the mature E1 beta subunit of the bovine branched-chain alpha-keto acid dehydrogenase complex was isolated from a lambda ZAP expression library. The bovine E1 beta cDNA is 1,393 base pairs in length. It encodes the entire mature E1 beta subunit consisting of 342 amino acid residues and a partial mitochondrial targeting presequence of 26 residues. The calculated molecular mass of the mature bovine E1 beta subunit is 37,776 daltons, and the calculated isoelectric point is pI 5.04. The mature bovine E1 beta subunit was expressed in Escherichia coli via the pKK233-2 vector in the presence of isopropyl beta-D-thiogalactopyranoside (IPTG). When expression was induced by IPTG at 37 degrees C, the soluble recombinant E1 beta subunit existed as a single high molecular weight form (Mr congruent to 3.5 x 10(5)), which sedimented during sucrose gradient ultracentrifugation at 2 x 10(5) x g. However, lowering the induction temperature to 25 degrees C resulted in the occurrence of both high and low molecular weight forms of the recombinant E1 beta protein. The low molecular weight form (Mr congruent to 9.1 x 10(4)) remained soluble after sucrose gradient centrifugation and was utilized in binding studies with a series of truncated recombinant E2 proteins. The results showed that the E1 beta subunit bound to the region between Ala-115 and Lys-150 of the E2 chain, which lay within the putative E3-binding domain. In contrast, the recombinant E1 alpha subunit did not bind the E2 component. The data suggest an apparent binding order of E2-E1 beta-E1 alpha, which supports and extends the model of E2 inner core deduced previously from the data of scanning transmission electron microscopy (Hackert, M.L., Xu, W.-X., Oliver, R.M., Wall, J.S., Hainfeld, J.F., Mullinax, T.R., and Reed, L.J. (1989) Biochemistry 28, 6816-6821). The relatively inaccessible topology of E1 beta may explain the lack of antigenicity and resistance to limited proteolysis of this subunit as it exists in the complex.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1881-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:1730724-3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide), pubmed-meshheading:1730724-Amino Acid Sequence, pubmed-meshheading:1730724-Animals, pubmed-meshheading:1730724-Base Sequence, pubmed-meshheading:1730724-Binding Sites, pubmed-meshheading:1730724-Cattle, pubmed-meshheading:1730724-Cloning, Molecular, pubmed-meshheading:1730724-Escherichia coli, pubmed-meshheading:1730724-Gene Library, pubmed-meshheading:1730724-Ketone Oxidoreductases, pubmed-meshheading:1730724-Macromolecular Substances, pubmed-meshheading:1730724-Mitochondria, Liver, pubmed-meshheading:1730724-Models, Structural, pubmed-meshheading:1730724-Molecular Sequence Data, pubmed-meshheading:1730724-Multienzyme Complexes, pubmed-meshheading:1730724-Plasmids, pubmed-meshheading:1730724-Recombinant Proteins, pubmed-meshheading:1730724-Restriction Mapping
pubmed:year
1992
pubmed:articleTitle
Cloning and expression in Escherichia coli of mature E1 beta subunit of bovine mitochondrial branched-chain alpha-keto acid dehydrogenase complex. Mapping of the E1 beta-binding region on E2.
pubmed:affiliation
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9083.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't