Abstract |
The growth of Pyrobaculum aerophilum on yeast extract and nitrate was stimulated by the addition of maltose. Extracts of maltose/yeast extract/nitrate-grown cells contained all enzyme activities of a modified Embden-Meyerhof (EM) pathway, including ATP-dependent glucokinase, phosphoglucose isomerase, ATP-dependent 6-phosphofructokinase, fructose-1,6-phosphate aldolase, triose-phosphate isomerase, GAPOR, phosphoglycerate mutase, enolase and pyruvate kinase. The activity of GAPOR was stimulated about fourfold by maltose, indicating a role in sugar degradation. GAPOR was purified 200-fold to homogeneity and characterized as a 67 kDa monomeric, extremely thermostable protein. The enzyme showed high specificity for glyceraldehyde-3-phosphate and did not use glyceraldehyde, acetaldehyde or formaldehyde as substrates. By matrix-assisted laser desorption/ionization-time of flight analysis of the purified enzyme, ORF PA1029 was identified as a coding gene, gapor, in the sequenced genome of Pyrobaculum aerophilum. The data indicate that the (micro)aerophilic Pyrobaculum aerophilum contains a functional GAPOR as part of a modified EM pathway. Cells of the strictly aerobic crenarchaeon Aeropyrum pernix also contain enzyme activities of a modified EM pathway similar to that of Pyrobaculum aerophilum, except that a GAPN activity replaces GAPOR activity.
|
Authors | Matthias Reher, Susanne Gebhard, Peter Schönheit |
Journal | FEMS microbiology letters
(FEMS Microbiol Lett)
Vol. 273
Issue 2
Pg. 196-205
(Aug 2007)
ISSN: 0378-1097 [Print] England |
PMID | 17559573
(Publication Type: Journal Article)
|
Chemical References |
- Glyceraldehyde-3-Phosphate Dehydrogenases
- glyceraldehyde-3-phosphate ferredoxin oxidoreductase
|
Topics |
- Aeropyrum
(classification, enzymology)
- Carbohydrate Metabolism
- Glyceraldehyde-3-Phosphate Dehydrogenases
(isolation & purification, metabolism)
- Glycolysis
(physiology)
- Phylogeny
- Pyrobaculum
(classification, enzymology)
- Substrate Specificity
|