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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2004-6-14
pubmed:abstractText
Comparative analysis of the domain architectures of the beta, beta', and sigma(70) subunits of bacterial DNA-dependent RNA polymerases (DdRp), combined with sequence-based phylogenetic analysis, revealed a fundamental split among bacteria. DNA-dependent RNA polymerase subunits of Group I, which includes Proteobacteria, Aquifex, Chlamydia, Spirochaetes, Cytophaga-Chlorobium, and Planctomycetes, are characterized by three distinct inserts, namely a Sandwich Barrel Hybrid Motif domain in the beta subunit, a beta-beta' module (BBM) 1 domain in the beta' subunit, and a distinct helical module in the sigma subunit. The DdRp subunits of remaining bacteria, which comprise Group II, lack these inserts, although some additional inserted domains are present in individual lineages. The separation of bacteria into Group I and Group II is generally compatible with the topologies of phylogenetic trees of the conserved regions of DdRp subunits and concatenated ribosomal proteins and might represent the primary bifurcation in bacterial evolution. A striking deviation from this evolutionary pattern is Aquifex whose DdRp subunits cluster within Group I, whereas phylogenetic analysis of ribosomal proteins identifies Aquifex as grouping with Thermotoga another bacterial hyperthemophile belonging to Group II. The inferred evolutionary scenario for the DdRp subunits includes domain accretion and rearrangement, with some likely horizontal transfer events. Although evolution of bacterial DdRp appeared to be generally dominated by vertical inheritance, horizontal transfer of complete genes for all or some of the subunits, resulting in displacement of the ancestral genes, might have played a role in several lineages, such as Aquifex, Thermotoga, and Fusobacterium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
335
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
73-88
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Evolution of bacterial RNA polymerase: implications for large-scale bacterial phylogeny, domain accretion, and horizontal gene transfer.
pubmed:affiliation
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
pubmed:publicationType
Journal Article