| pubmed-article:4083897 | rdf:type | pubmed:Citation | lld:pubmed |
| pubmed-article:4083897 | lifeskim:mentions | umls-concept:C0085467 | lld:lifeskim |
| pubmed-article:4083897 | lifeskim:mentions | umls-concept:C0376315 | lld:lifeskim |
| pubmed-article:4083897 | lifeskim:mentions | umls-concept:C0008515 | lld:lifeskim |
| pubmed-article:4083897 | pubmed:issue | 2 | lld:pubmed |
| pubmed-article:4083897 | pubmed:dateCreated | 1986-1-30 | lld:pubmed |
| pubmed-article:4083897 | pubmed:abstractText | Acinetobacter calcoaceticus belongs to a large phylogenetic cluster of gram-negative procaryotes that all utilize a bifunctional P-protein (chorismate mutase-prephenate dehydratase) [EC 5.4.99.5-4.2.1.51] for phenylalanine biosynthesis. These two enzyme activities from Ac. calcoaceticus were inseparable by gel-filtration or DEAE-cellulose chromatography. The molecular weight of the P-protein in the absence of effectors was 65,000. In the presence of L-tyrosine (dehydratase activator) or L-phenylalanine (inhibitor of both P-protein activities), the molecular weight increased to 122,000. Maximal activation (23-fold) of prephenate dehydratase was achieved at 0.85 mM L-tyrosine. Under these conditions, dehydratase activity exhibited a hysteretic response to increasing protein concentration. Substrate saturation curves for prephenate dehydratase were hyperbolic at L-tyrosine concentrations sufficient to give maximal activation (yielding a Km,app of 0.52 mM for prephenate), whereas at lower L-tyrosine concentrations the curves were sigmoidal. Dehydratase activity was inhibited by L-phenylalanine, and exhibited cooperative interactions for inhibitor binding. A Hill plot yielded an n' value of 3.1. Double-reciprocal plots of substrate saturation data obtained in the presence of L-phenylalanine indicated cooperative interactions for prephenate in the presence of inhibitor. The n values obtained were 1.4 and 3.0 in the absence or presence of 0.3 mM L-phenylalanine, respectively. The hysteretic response of chorismate mutase activity to increasing enzyme concentration was less dramatic than that of prephenate dehydratase. A Km,app for chorismate of 0.63 mM was obtained. L-Tyrosine did not affect chorismate mutase activity, but mutase activity was inhibited both by L-phenylalanine and by prephenate. Interpretations are given about the physiological significance of the overall pattern of allosteric control of the P-protein, and the relationship between this control and the effector-induced molecular-weight transitions. The properties of the P-protein in Acinetobacter are considered within the context of the ubiquity of the P-protein within the phylogenetic cluster to which this genus belongs. | lld:pubmed |
| pubmed-article:4083897 | pubmed:grant | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:language | eng | lld:pubmed |
| pubmed-article:4083897 | pubmed:journal | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:citationSubset | IM | lld:pubmed |
| pubmed-article:4083897 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:4083897 | pubmed:status | MEDLINE | lld:pubmed |
| pubmed-article:4083897 | pubmed:month | Dec | lld:pubmed |
| pubmed-article:4083897 | pubmed:issn | 0003-9861 | lld:pubmed |
| pubmed-article:4083897 | pubmed:author | pubmed-author:JensenR ARA | lld:pubmed |
| pubmed-article:4083897 | pubmed:author | pubmed-author:ByngG SGS | lld:pubmed |
| pubmed-article:4083897 | pubmed:author | pubmed-author:BerryAA | lld:pubmed |
| pubmed-article:4083897 | pubmed:issnType | Print | lld:pubmed |
| pubmed-article:4083897 | pubmed:volume | 243 | lld:pubmed |
| pubmed-article:4083897 | pubmed:owner | NLM | lld:pubmed |
| pubmed-article:4083897 | pubmed:authorsComplete | Y | lld:pubmed |
| pubmed-article:4083897 | pubmed:pagination | 470-9 | lld:pubmed |
| pubmed-article:4083897 | pubmed:dateRevised | 2007-11-14 | lld:pubmed |
| pubmed-article:4083897 | pubmed:meshHeading | pubmed-meshheading:4083897-... | lld:pubmed |
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| pubmed-article:4083897 | pubmed:year | 1985 | lld:pubmed |
| pubmed-article:4083897 | pubmed:articleTitle | Interconvertible molecular-weight forms of the bifunctional chorismate mutase-prephenate dehydratase from Acinetobacter calcoaceticus. | lld:pubmed |
| pubmed-article:4083897 | pubmed:publicationType | Journal Article | lld:pubmed |
| pubmed-article:4083897 | pubmed:publicationType | Research Support, U.S. Gov't, P.H.S. | lld:pubmed |
| pubmed-article:4083897 | pubmed:publicationType | Research Support, U.S. Gov't, Non-P.H.S. | lld:pubmed |
