Comparative genomic and phylogenetic analyses of gammaproteobacterial glg genes traced the origin of the Escherichia coli glycogen glgBXCAP operon to the last common ancestor of the sister orders Enterobacteriales and Pasteurellales

© 2015 Almagro et al. Production of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have carried out a comparative analysis of the presence, copy number and arrangement of glg genes in all lineages of the Gammaproteobacteria. These analyses revealed large variations in glg gene presence, copy number and arrangements among different gammaproteobacterial lineages. However, the glgBXCAP arrangement was remarkably conserved in all glg-possessing species of the orders Enterobacteriales and Pasteurellales (the E/P group). Subsequent phylogenetic analyses of glg genes present in the Gammaproteobacteria and in other main bacterial groups indicated that glg genes have undergone a complex evolutionary history in which horizontal gene transfer may have played an important role. These analyses also revealed that the E/P glgBXCAP genes (a) share a common evolutionary origin, (b) were vertically transmitted within the E/P group, and (c) are closely related to glg genes of some phylogenetically distant betaproteobacterial species. The overall data allowed tracing the origin of the E. coli glgBXCAP operon to the last common ancestor of the E/P group, and also to uncover a likely glgBXCAP transfer event from the E/P group to particular lineages of the Betaproteobacteria.

Bibliographic Details

Main Authors:	Almagro, Goizeder, Viale, Alejandro M., Montero, Manuel, Rahimpour, Mehdi, Muñoz Pérez, Francisco José, Baroja-Fernández, Edurne, Bahaji, Abdellatif, Zúñiga, Manuel, González-Candelas, Fernando, Pozueta Romero, Javier
Other Authors:	Comisión Interministerial de Ciencia y Tecnología, CICYT (España)
Format:	artículo biblioteca
Published:	Public Library of Science 2015-01-21
Subjects:	glycogen, Amino acid sequence, Genome evolution, Bacterial evolution, Phylogenetic analysis,
Online Access:	http://hdl.handle.net/10261/110636 http://dx.doi.org/10.13039/501100007273 http://dx.doi.org/10.13039/501100000780 http://dx.doi.org/10.13039/501100003339 http://dx.doi.org/10.13039/501100004837
Tags:	Add Tag No Tags, Be the first to tag this record!