Propionigenium modestum: a separate line of descent within the eubacteria

Abstract

Summary The complete nucleotide sequence of 16S rRNA from Propionigenium modestum was determined and compared with 380 16S rRNA sequences from representatives of all eu‐ and archaebacterial phyla known so far. The phylogenetic analysis of this data set indicated P. modestum to represent a new separated line of descent within the radiation of eubacterial phyla moderately related to cyano‐bacteria and Gram‐positive bacteria with low DNA GC content.

Phylogenetic analyses of the homologous transmembrane channel-forming proteins of the F0F1-ATPases of bacteria, chloroplasts and mitochondria

“…The c- and a-subunits of this enzyme complex cluster more closely with those of cyanobacteria and chloroplasts than with those of other bacteria ( and ), but the b-subunit clusters with the bacterial F-type ATPase b-subunits, being situated closer to the Gram-negative purple bacterial cluster of these proteins than to the Gram-positive bacterial cluster of these proteins. P. modestum has been reported to represent a new, separate line of descent within the bacterial phyla, moderately related to the cyanobacteria (Both et al , 1991). Since the b-subunit of P. modestum does not cluster as do the a- and c-subunits on their respective trees, the b-subunit may have been acquired by horizontal transmission from another bacterium.…”