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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
12
|
| pubmed:dateCreated |
1978-8-28
|
| pubmed:abstractText |
The main phosphofructokinase of Escherichia coli (PFK I) is an extensively studied allosteric enzyme specified by the pfkA gene. A nonallosteric phosphofructokinase was reported (Fraenkel, D.G., Kotlarz, D., and Bluc, H. (1973) J. Biol. Chem. 248, 4865-4866) in strains carrying the pfkB1 mutation, a suppressor of pfkA mutants, and very low levels of this enzyme have also been detected in strains not carrying the suppressor (i.e. pfkB+). The nonallosteric protein has now been prepared pure from three strains, one carrying pfkB1 and pfkA+, one carrying pfkB1 and completely deleted for pfkA, and one carrying pfkB+ and also deleted for pfkA. It is apparently the same enzyme (PFK II) in all three strains, which shows that pfkB1 is a mutation affecting the amount of a normally minor isozyme. PFK II is a tetramer of slightly larger subunit molecular weight than PFK I (36,000 and 34,000, respectively). No immunological cross-reactivity was detected between PFK II and PFK I. Unlike PFK I, PFK II does not show cooperative interactions with fructose-6-P, inhibition by P-enolpyruvate, or activation by ADP. Also unlike PFK I, PFK II is somewhat sensitive to inhibition by fructose-1,6-P2 and can use tagatose-6-P as substrate. Both enzymes can perform the reverse reaction, fructose-6-P + ATP from fructose-1,6-P2 + ADP in vitro, but not in vivo. The normal function of PFK II is not known.
|
| 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 |
25
|
| pubmed:volume |
253
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
4350-5
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading | |
| pubmed:year |
1978
|
| pubmed:articleTitle |
Phosphofructokinases from Escherichia coli. Purification and characterization of the nonallosteric isozyme.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|