Size comparisons among integral membrane transport protein homologues in bacteria, Archaea, and Eucarya.

ABSTRACT: Integral membrane proteins from over 20 ubiquitous families of channels, secondary carriers, and primary active transporters were analyzed for average size differences between homologues from the three domains of life: Bacteria, Archaea, and Eucarya. The results showed that while eucaryotic homologues are consistently larger than their bacterial counterparts, archaeal homologues are significantly smaller. These size differences proved to be due primarily to variations in the sizes of hydrophilic domains localized to the N termini, the C termini, or specific loops between transmembrane alpha-helical spanners, depending on the family. Within the Eucarya domain, plant homologues proved to be substantially smaller than their animal and fungal counterparts. By contrast, extracytoplasmic recepto

SUBMITTER: Chung YJ 

PROVIDER: S-EPMC94969 | biostudies-literature | 2001 Feb

REPOSITORIES: biostudies-literature