A putative ATP-binding cassette transporter YbdA involved in sporulation of Bacillus subtilis

Insertional mutagenesis with mini-Tn10 was performed to identify new genes involved in sporulation of Bacillus subtilis. Here, we report on the charac terization of the ybdA locus, which encodes a putative ATP-binding cassette transporter. The ybdA gene is the 6th cistron of the putative ybcOPQST-ybd ABDE operon. A deletion mutation in ybdA and an insertional mutation in ybd B exhibited highly oligosporogenous phenotypes and led to a decrease in the transcription controlled by Spo0A, which is a key response regulator requi red for the initiation of sporulation. We further observed that the transcr iption of this operon was strongly induced after the end of the exponential growth phase in the wild-type strain, but not in a spo0A null mutant. Our data suggest that the YbdA and YbdB proteins are able to affect incorporati on of nutrient signals during initiation of sporulation and may act as comp onents of positive feedback systems of Spo0A activation. (C) 2001 Federatio n of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.