Occurrence of the hsp70 (dnaK) gene was investigated in various members of the domain Archaeacomprising both euryarchaeotes and crenarchaeotes and in the hyperthermophilic bacteria Aquifex pyrophilus andThermotoga maritima representing the deepest offshoots in phylogenetic trees of bacterial 16S rRNA sequences. The gene was not detected in 8 of 10 archaea examined but was found in A. pyrophilus and T. maritima, from which it was cloned and sequenced. Comparative analyses of the HSP70 amino acid sequences encoded in these genes, and others in the databases, showed that (i) in accordance with the vicinities seen in rRNA-based trees, the proteins from A. pyrophilus and T. maritima form a thermophilic cluster with that from the green nonsulfur bacteriumThermomicrobium roseum and are unrelated to their counterparts from gram-positive bacteria, proteobacteria/mitochondria, chlamydiae/spirochetes, deinococci, and cyanobacteria/chloroplasts; (ii) the T. maritima HSP70 clusters with the homologues from the archaea Methanobacterium thermoautotrophicum andThermoplasma acidophilum, in contrast to the postulated unique kinship between archaea and gram-positive bacteria; and (iii) there are exceptions to the reported association between an insert in HSP70 and gram negativity, or vice versa, absence of insert and gram positivity. Notably, the HSP70 from T. maritima lacks the insert, although T. maritima is phylogenetically unrelated to the gram-positive bacteria. These results, along with the absence ofhsp70 (dnaK) in various archaea and its presence in others, suggest that (i) different taxa retained either one or the other of two hsp70 (dnaK) versions (with or without insert), regardless of phylogenetic position; and (ii) archaea are aboriginally devoid of hsp70(dnaK), and those that have it must have received it from phylogenetically diverse bacteria via lateral gene transfer events that did not involve replacement of an endogenous hsp70(dnaK) gene.

Discontinuous occurence of the hsp70(dnaK) gene among Archea and sequence features of HSP70 suggest a novel outlook on phylogenies inferred from this protein / Gribaldo, S; Lumia, V; Creti, R; CONWAY DE MACARIO, E; Sanangelantoni, Anna Maria; Cammarano, P.. - In: JOURNAL OF BACTERIOLOGY. - ISSN 0021-9193. - 181:(1999), pp. 434-443.

Discontinuous occurence of the hsp70(dnaK) gene among Archea and sequence features of HSP70 suggest a novel outlook on phylogenies inferred from this protein

SANANGELANTONI, Anna Maria;
1999

Abstract

Occurrence of the hsp70 (dnaK) gene was investigated in various members of the domain Archaeacomprising both euryarchaeotes and crenarchaeotes and in the hyperthermophilic bacteria Aquifex pyrophilus andThermotoga maritima representing the deepest offshoots in phylogenetic trees of bacterial 16S rRNA sequences. The gene was not detected in 8 of 10 archaea examined but was found in A. pyrophilus and T. maritima, from which it was cloned and sequenced. Comparative analyses of the HSP70 amino acid sequences encoded in these genes, and others in the databases, showed that (i) in accordance with the vicinities seen in rRNA-based trees, the proteins from A. pyrophilus and T. maritima form a thermophilic cluster with that from the green nonsulfur bacteriumThermomicrobium roseum and are unrelated to their counterparts from gram-positive bacteria, proteobacteria/mitochondria, chlamydiae/spirochetes, deinococci, and cyanobacteria/chloroplasts; (ii) the T. maritima HSP70 clusters with the homologues from the archaea Methanobacterium thermoautotrophicum andThermoplasma acidophilum, in contrast to the postulated unique kinship between archaea and gram-positive bacteria; and (iii) there are exceptions to the reported association between an insert in HSP70 and gram negativity, or vice versa, absence of insert and gram positivity. Notably, the HSP70 from T. maritima lacks the insert, although T. maritima is phylogenetically unrelated to the gram-positive bacteria. These results, along with the absence ofhsp70 (dnaK) in various archaea and its presence in others, suggest that (i) different taxa retained either one or the other of two hsp70 (dnaK) versions (with or without insert), regardless of phylogenetic position; and (ii) archaea are aboriginally devoid of hsp70(dnaK), and those that have it must have received it from phylogenetically diverse bacteria via lateral gene transfer events that did not involve replacement of an endogenous hsp70(dnaK) gene.
Discontinuous occurence of the hsp70(dnaK) gene among Archea and sequence features of HSP70 suggest a novel outlook on phylogenies inferred from this protein / Gribaldo, S; Lumia, V; Creti, R; CONWAY DE MACARIO, E; Sanangelantoni, Anna Maria; Cammarano, P.. - In: JOURNAL OF BACTERIOLOGY. - ISSN 0021-9193. - 181:(1999), pp. 434-443.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11381/1461625
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 86
  • ???jsp.display-item.citation.isi??? ND
social impact