Not all transmembrane helices are born equal: Towards the extension of the sequence homology concept to membrane proteins.

ABSTRACT:

Background

Sequence homology considerations widely used to transfer functional annotation to uncharacterized protein sequences require special precautions in the case of non-globular sequence segments including membrane-spanning stretches composed of non-polar residues. Simple, quantitative criteria are desirable for identifying transmembrane helices (TMs) that must be included into or should be excluded from start sequence segments in similarity searches aimed at finding distant homologues.

Results

We found that there are two types of TMs in membrane-associated proteins. On the one hand, there are so-called simple TMs with elevated hydrophobicity, low sequence complexity and extraordinary enrichment in long aliphatic residues. They merely serve as membrane-anchoring device.

SUBMITTER: Wong WC 

PROVIDER: S-EPMC3217874 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature