Open AccessPrimary structure of major outer membrane protein I of Escherichia coli B/r.
Author(s) -
Robert Chen,
C. Kramer,
Waldtraud Schmidmayr,
Ulf Henning
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.10.5014
Subject(s) - glycophorin , transmembrane protein , porin , escherichia coli , polarity (international relations) , peptide sequence , protein primary structure , chemistry , amino acid , bacterial outer membrane , amino acid residue , polypeptide chain , transmembrane domain , sequence (biology) , biochemistry , protein structure , membrane protein , stereochemistry , crystallography , membrane , receptor , cell , gene
The amino acid sequence of the pore-forming outer membrane protein I (porin) from Escherichia coli B/r has been determined. The polypeptide contains 340 amino acid residues resulting in a molecular weight of 37,205. The transmembrane polypeptide has no stretches of nonpolar residues, uninterrupted by charged side chains, longer than 11 amino acid residues. Regarding polarity, the chain can be subdivided into three regions: a distinctly hydrophilic region between residues 1 and 82 (51.2% polarity), a fairly nonpolar region between residues 83 and 194 (33.9% polarity), and a more hydrophilic region up to the COOH terminus (48% polarity). These results are interpreted as evidence against a simple transmembrane structure in which the membrane is spanned by a single contiguous sequence of hydrophobic amino acids, as has been proposed, for example, for glycophorin.