Comparative Genomic Analyses of the Bacterial Phosphotransferase System

Abstract

SUMMARY We report analyses of 202 fully sequenced genomes for homologues of known protein constituents of the bacterial phosphoenolpyruvate-dependent phosphotransferase system (PTS). These included 174 bacterial, 19 archaeal, and 9 eukaryotic genomes. Homologues of PTS proteins were not identified in archaea or eukaryotes, showing that the horizontal transfer of genes encoding PTS proteins has not occurred between the three domains of life. Of the 174 bacterial genomes (136 bacterial species) analyzed, 30 diverse species have no PTS homologues, and 29 species have cytoplasmic PTS phosphoryl transfer protein homologues but lack recognizable PTS permeases. These soluble homologues presumably function in regulation. The remaining 77 species possess all PTS proteins required for the transport and phosphorylation of at least one sugar via the PTS. Up to 3.2% of the genes in a bacterium encode PTS proteins. These homologues were analyzed for family association, range of protein types, domain organization, and organismal distribution. Different strains of a single bacterial species often possess strikingly different complements of PTS proteins. Types of PTS protein domain fusions were analyzed, showing that certain types of domain fusions are common, while others are rare or prohibited. Select PTS proteins were analyzed from different phylogenetic standpoints, showing that PTS protein phylogeny often differs from organismal phylogeny. The results document the frequent gain and loss of PTS protein-encoding genes and suggest that the lateral transfer of these genes within the bacterial domain has played an important role in bacterial evolution. Our studies provide insight into the development of complex multicomponent enzyme systems and lead to predictions regarding the types of protein-protein interactions that promote efficient PTS-mediated phosphoryl transfer.

Growth-dependent Phosphorylation of the PtsN (EIINtr) Protein of Pseudomonas putida

“…1A, the archetypal PTS system consists of enzyme I (EI), HPr, and enzyme II (EII). Due to their ability to interact with other proteins in the cytoplasm, the set of phosphorylated and nonphosphorylated PTS proteins (more often HPr and EIIA) fulfills regulatory functions as diverse as catabolite repression, chemotaxis, the regulation of cyclic AMP synthesis, or nitrogen assimilation (2)(3)(4). Apart from these PTS components involved in sugar transport, many prokaryotes also have PTS branches that are not involved in carbohydrate traffic.…”

HPr antagonizes the anti-σ 70 activity of Rsd in Escherichia coli

“…The PTS is a multicomponent system that catalyzes the concomitant phosphorylation and translocation of numerous sugar substrates across the cytoplasmic membrane. This system consists of two general components, enzyme I (EI) and the histidine-containing phosphocarrier protein HPr, which are common to all PTS sugars, along with many sugar-specific components collectively known as enzyme IIs (EIIs) (1,2).…”

Cellular and organellar membrane-associated proteins in haloarchaea: Perspectives on the physiological significance and biotechnological applications

“…After analysis of all 16 completely sequenced haloarchaeal genomes, we found that nine haloarchaea have PTS homologues (Figure 1 PtsI autophosphorylates from PEP and transfers a phosphoryl group to Hpr, and PtsA becomes phosphorylated by the phosphorylated-Hpr and passes the phosphoryl group on to PtsB. PtsC functions as a permease and sugar-specific receptor located in the cell membrane [46]. PtsA, PtsB and PtsC are components of an enzyme complex named enzyme II.…”