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Titolo:
Contribution of the bacterial endosymbiont to the biosynthesis of pyrimidine nucleotides in the deep-sea tube worm Riftia pachyptila
Autore:
Minic, Z; Simon, V; Penverne, B; Gaill, F; Herve, G;
Indirizzi:
Univ Paris 06, CNRS, UMR 7631, Lab Biochim Signaux Regulateurs Cellulaires& Mol, F-75006 Paris, France Univ Paris 06 Paris France F-75006 llulaires& Mol, F-75006 Paris, France Univ Paris 06, CNRS UPR Roscoff 9042, Inst Natl Sci Univers, Biol Marine Lab, F-75252 Paris, France Univ Paris 06 Paris France F-75252 iol Marine Lab, F-75252 Paris, France
Titolo Testata:
JOURNAL OF BIOLOGICAL CHEMISTRY
fascicolo: 26, volume: 276, anno: 2001,
pagine: 23777 - 23784
SICI:
0021-9258(20010629)276:26<23777:COTBET>2.0.ZU;2-P
Fonte:
ISI
Lingua:
ENG
Soggetto:
RIBOSOMAL-RNA SEQUENCES; ESCHERICHIA-COLI; GLUTAMINE-SYNTHETASE; CHEMOAUTOTROPHIC SYMBIONTS; ASPARTATE-TRANSCARBAMYLASE; MULTIFUNCTIONAL PROTEIN; NITRATE RESPIRATION; CELLS; JONES; PURIFICATION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Herve, G Univ Paris 06, CNRS, UMR 7631, Lab Biochim Signaux Regulateurs Cellulaires& Mol, 96 Blvd Raspail, F-75006 Paris, France Univ Paris 06 96 Blvd Raspail Paris France F-75006 Paris, France
Citazione:
Z. Minic et al., "Contribution of the bacterial endosymbiont to the biosynthesis of pyrimidine nucleotides in the deep-sea tube worm Riftia pachyptila", J BIOL CHEM, 276(26), 2001, pp. 23777-23784

Abstract

The deep-sea tube worm Riftia pachyptila (Vestimentifera) from hydrothermal vents lives in an intimate symbiosis with a sulfur-oxidizing bacterium. That involves specific interactions and obligatory metabolic exchanges between the two organisms. In this work, we analyzed the contribution of the twopartners to the biosynthesis of pyrimidine nucleotides through both the "de novo" and "salvage" pathways. The first three enzymes of the de novo pathway, carbamyl-phosphate synthetase, aspartate transcarbamylase, and dihydroorotase, were present only in the trophosome, the symbiont-containing tissue. The study of these enzymes in terms of their catalytic and regulatory properties in both the trophosome and the isolated symbiotic bacteria provided a clear indication of the microbial origin of these enzymes. In contrast,the succeeding enzymes of this de novo pathway, dihydroorotate dehydrogenase and orotate phosphoribosyltransferase, were present in all body parts ofthe worm. This finding indicates that the animal is fully dependent on thesymbiont for the de novo biosynthesis of pyrimidines. In addition, it suggests that the synthesis of pyrimidines in other tissues is possible from the intermediary metabolites provided by the trophosomal tissue and from nucleic acid degradation products since the enzymes of the salvage pathway appear to be present in all tissues of the worm. Analysis of these salvage pathway enzymes in the trophosome strongly suggested that these enzymes belong to the worm. In accordance with this conclusion, none of these enzyme activities was found in the isolated bacteria. The enzymes involved in the production of the precursors of carbamyl phosphate and nitrogen assimilation, glutamine synthetase and nitrate reductase, were also investigated, and it appears that these two enzymes are present in the bacteria.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 01:58:03