The structure of porin from Rhodobacter capsulatus at 1.8 Å resolution

Abstract

The structure of the porin from Rhodobacter capsulanus was determined at a resolution of 1.8 Å. The analysis started from a closely related crystal structure that had been solved at a medium resolution of 3 Å using multiple isomorphous replacement and solvent flattening. The new structure contains the complete sequence of 301 amino acid residues. Refinement of the model is under way: the present R‐factor is 22% with good geometry. Except for the lengths of several loops, the resulting chain fold corresponds to the medium resolution model. The membrane channel is lined by a large number of ionogenic side chains with characteristic segregation of differently charged groups.