Journal article

A COMMON CHANNEL-FORMING MOTIF IN EVOLUTIONARILY DISTANT PORINS

RA PAUPTIT, T SCHIRMER, JN JANSONIUS, JP ROSENBUSCH, MW PARKER, AD TUCKER, D TSERNOGLOU, MS WEISS, GE SCHULZ

JOURNAL OF STRUCTURAL BIOLOGY | ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS | Published : 1991

Abstract

Four new crystal packings of Escherichia coli porins are presented (phosphoporin, maltoporin, and two crystal forms of matrix porin). These were determined by molecular replacement methods using a polyalanine trial model acquired from the refined coordinates of porin from Rhodobacter capsulatus. The successful molecular replacement shows that the dominant motif found in R. capsulatus porin (a 16-stranded antiparallel beta-barrel) also applies to the E. coli porins, despite the lack of significant amino acid sequence homology. A 30 degrees-40 degrees tilt of the beta-strands with respect to the membrane normal was derived from the intensity distributions in the X-ray diffraction patterns for ..

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