RT Journal Article SR Electronic(1) A1 Mills, James A1 Greenwood, Jacqueline A. A1 Wyborn, Neil R. A1 Williams, Steven G. A1 Jones, Colin W.YR 1997 T1 An outer-membrane porin inducible by short-chain amides and urea in the methylotrophic bacterium Methylophilus methylotrophus JF Microbiology, VO 143 IS 7 SP 2373 OP 2379 DO https://doi.org/10.1099/00221287-143-7-2373 PB Microbiology Society, SN 1465-2080, AB Summary: The fmdA and fmdB genes encoding formamidase and a putative regulatory protein, respectively, from the methylotrophic bacterium Methylophilus methylotrophus were recloned with additional flanking DNA (pSW1). fmdC, encoding a weakly hydrophilic protein containing an N-terminal signal sequence, was identified upstream of fmdAB. The derived amino acid sequence of mature FmdC (Mr 39204) showed that it was rich in -sheet and aromatic amino acids, and exhibited significant similarities to several outer-membrane porins from other bacteria. Cell fractionation studies showed that the protein was located in the outer membrane. Mature FmdC was purified and shown to consist of a single type of subunit (M r 40000) with the predicted N-terminal amino acid sequence (GATISF-). SDS-PAGE and Western blotting of cells grown in continuous culture under various conditions showed that mature FmdC was induced by formamide, acetamide and urea, repressed by excess ammonia, and over-expressed during prolonged growth under formamide limitation. It is concluded that mature FmdC is a porin involved in the transport of short-chain amides and urea through the outer membrane of M. methylotrophus under conditions where these nitrogen sources are present at very low concentration., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-143-7-2373