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Titolo:
MOLECULAR EVOLUTIONARY ANALYSIS OF THE THIAMINE-DIPHOSPHATE-DEPENDENTENZYME, TRANSKETOLASE
Autore:
SCHENK G; LAYFIELD R; CANDY JM; DUGGLEBY RG; NIXON PF;
Indirizzi:
UNIV QUEENSLAND,DEPT BIOCHEM,CTR PROTEIN STRUCT FUNCT & ENGN ST LUCIAQLD 4072 AUSTRALIA UNIV QUEENSLAND,DEPT BIOCHEM,CTR PROTEIN STRUCT FUNCT & ENGN ST LUCIAQLD 4072 AUSTRALIA UNIV QUEENSLAND,CTR CELLULAR & MOL BIOL ST LUCIA QLD 4072 AUSTRALIA QUEENSLAND UNIV TECHNOL,SCH LIFE SCI,CTR MOL BIOTECHNOL BRISBANE QLD 4001 AUSTRALIA
Titolo Testata:
Journal of molecular evolution
fascicolo: 5, volume: 44, anno: 1997,
pagine: 552 - 572
SICI:
0022-2844(1997)44:5<552:MEAOTT>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
AMINO-ACID-SEQUENCE; LIVER ALCOHOL-DEHYDROGENASE; PENTOSE-PHOSPHATE PATHWAY; REFINED CRYSTAL-STRUCTURE; D-LACTATE DEHYDROGENASE; ESCHERICHIA-COLI K-12; SACCHAROMYCES-CEREVISIAE; NUCLEOTIDE-SEQUENCE; DNA-SEQUENCES; STREPTOCOCCUS-PNEUMONIAE;
Keywords:
TRANSKETOLASE; THIAMINE DIPHOSPHATE; TRANSKETOLASE MOTIF; EVOLUTION; PHYLOGENETIC TREES; MOLECULAR CLOCK;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
97
Recensione:
Indirizzi per estratti:
Citazione:
G. Schenk et al., "MOLECULAR EVOLUTIONARY ANALYSIS OF THE THIAMINE-DIPHOSPHATE-DEPENDENTENZYME, TRANSKETOLASE", Journal of molecular evolution, 44(5), 1997, pp. 552-572

Abstract

Members of the transketolase group of thiamine-diphosphate-dependent enzymes from 17 different organisms including mammals, yeast, bacteria, and plants have been used for phylogenetic reconstruction. Alignmentof the amino acid and DNA sequences for 21 transketolase enzymes and one putative transketolase reveals a number of highly conserved regions and invariant residues that are of predicted importance for enzyme activity, based on the crystal structure of yeast transketolase. One particular sequence of 36 residues has some similarities to the nucleotide-binding motif and we designate it as the transketolase motif. We report further evidence that the recP protein from Streptococcus pneumoniae might be a transketolase and we list a number of invariant residues which might be involved in substrate binding. Phylogenies derived from the nucleotide and the amino acid sequences by various methods showa conventional clustering for mammalian, plant, and gramnegative bacterial transketolases, The branching order of the gram-positive bacteria could not be inferred reliably. The formaldehyde transketolase (sometimes known as dihydroxyacetone synthase) of the yeast Hansenula polymorpha appears to be orthologous to the mammalian enzymes but paralogous to the other yeast transketolases. The occurrence of more than one transketolase gene in some organisms is consistent with several gene duplications. The high degree of similarity in functionally important residues and the fact that the same kinetic mechanism is applicable to all characterized transketolase enzymes is consistent with the proposition that they are all derived from one common ancestral gene. Transketolase appears to be an ancient enzyme that has evolved slowly and might serve as a model for a molecular clock, at least within the mammalian clade.

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Documento generato il 04/12/20 alle ore 22:19:45