THE LUMQ GENE IS LINKED TO THE LUMP GENE AND THE LUX OPERON IN PHOTOBACTERIUM-LEIOGNATHI

The nucleotide sequence of the designated lumQ gene (EMBL accession No . U35231) from Photobacterium leiognathi PL741 has been determined, an d the encoded amino acid sequence is deduced. The LumQ protein has a c alculated M(r) of 28,416 and comprises 248 amino acid residues. The lu mQ gene is identified as the envY-like gene by significant similarity of the encoded protein with the EnvY and AdiY proteins of E. coli; the re the envY gene encodes the porin thermoregulatory protein EnvY, and the adiY gene encodes the putative transcriptional regulator protein A diY. It suggests that the fume gene of P. leiognathi is orthologous to the envY and adiY genes of E. coli. The function of the protein encod ed by the lumQ gene from P. leiognathi is not really defined yet, it i s likely to be the DNA-binding protein related to the araC and xylS fa mily of transcriptional regulators. The lumQ and lumP genes form the l um operon which linked to the lux operon, but run in the opposite dire ction. The gene order of the lum and the lux operon is -ter-lumQ-lumP- R&R-luxC-luxD-luxA-luxB-luxN-luxE-> (R&R: regulatory region; ter: tran scriptional terminator); whereas the regulatory region (R&R) includes two promoter systems, P-R-promoter for the lux operon and P-L-promoter for the two operon; ter is the transcriptional terminator of the lum operon. (C) 1995 Academic Press, Inc.