TCDB is operated by the Saier Lab Bioinformatics Group

1.B.7 The Rhodobacter PorCa Porin (RPP) Family

The Rhodobacter PorCa Protein, the only well characterized member of the RPP family, was the first porin to yield its three-dimensional structure by X-ray crystallography. It has a 16-stranded β-barrel structure similar to that of the members of the GBP (TC #1.B.1) family. Paupit et al. (1991) presented crystal structures of phosphoporin (PhoE; TC# 1.B.1.1.2), maltoporin (1.B.3.1.1; LamB) and Matrixporin (OmpF), all of E. coli, and found these have 3-d folds similar to that of the Rhodobacter porin, PorCa. It was not determined if this similarity is due to divergent evolution from a common ancestor or covergent evolution from dissimilar precursors. However, we have been able to demonstrate homology between members of families 1.B.1 and 1.B.7 using statistical means (M. Saier, unpublished results).

This family belongs to the: General Bacterial Porin (GBP) Superfamily.

References associated with 1.B.7 family:

Burdman, S., R. De Mot, J. Vanderleyden, Y. Okon, and E. Jurkevitch. (2000). Identification and characterization of the omaA gene encoding the major outer membrane protein of Azospirillum brasilense. DNA Seq 11: 225-237. 11092733
Jeanteur, D., J.H. Lakey and F. Pattus (1991). The bacterial porin superfamily: sequence alignment and structure prediction. Mol. Microbiol. 5: 2153-2164. 1662760
Jeanteur, D., J.H. Lakey and F. Pattus (1994). The porin superfamily: diversity and common features. In: Bacterial Cell Wall. Edited by Ghuysen, J.M., Hakenbeck, R. Elsevier, Amsterdam, pp. 363-380.
Kreusch, A. and G.E. Schultz (1994). Refined structure of the porin from Rhodopseudomonas blastica and comparison with the porin from Rhodobacter capsulatus. J. Mol. Biol. 243: 891-905. 7525973
Nikaido, H. (1992). Porins and specific channels of bacterial outer membranes. Mol. Microbiol. 6: 435-442. 1373213
Pauptit, R.A., T. Schirmer, J.N. Jansonius, J.P. Rosenbusch, M.W. Parker, A.D. Tucker, D. Tsernoglou, M.S. Weiss, and G.E. Schultz. (1991). A common channel-forming motif in evolutionarily distant porins. J Struct Biol 107: 136-145. 1725488
Schiltz, E., A. Kreusch, U. Nestel and G.E. Schulz (1991). Primary structure of porin from Rhodobacter capsulatus. Eur. J. Biochem. 199: 587-594. 1651239
Schulz, G.E. (1996). Porins: general to specific, native to engineered passive pores. Curr. Opin. Struc. Biol. 6: 485-490. 8794162
Weiss, M.S., T. Wacker, J. Weckesser, W. Welte and G.E. Schulz (1990). The three-dimensional structure of porin from Rhodobacter capsulatus at 3 Å resolution. FEBS Lett. 267: 268-272. 2165921