Disease relevance of phoU

• The order of the genes in this region has been established to be phoS-phoW-pstA(=phoT)-pstB-phoU counterclockwise on the E. coli genetic map [1].
• We report the isolation of phoB and phoU mutants of the bacterium Rhizobium (Sinorhizobium) meliloti [2].

High impact information on phoU

• Both PhoP and its truncated DBD domain were found to bind with high affinity to an upstream region of the pstS and phoRP-phoU promoters close to the -35 sequence of each of these promoters [3].
• However, only phoU mutants express both phoA and psiE constitutively [4].
• The pstA(=phoT), pstB and phoU genes are situated at 84 minutes on the Escherichia coli genetic map [1].
• Unexpectedly, delta phoU mutations had a severe growth defect, and this growth defect was (largely) alleviated by a compensatory mutation in the pstSCAB genes or in the phoBR operon, whose gene products positively regulate expression of the pstSCAB-phoU operon [5].
• Use of the rep technique for allele replacement to construct mutants with deletions of the pstSCAB-phoU operon: evidence of a new role for the PhoU protein in the phosphate regulon [5].

Biological context of phoU

• The amino acid composition and N-terminal amino acid sequence of the purified protein confirmed the reading frame established earlier for the phoU gene [6].
• In order to study such presumed interaction(s), mutants with defined deletions of the pstSCAB-phoU operon were made [5].
• The phoU mutant could be easily screened on agar plates containing 5-bromo-4-chloro-3-indolyl-phosphate (X-P(i)) after N-methyl-N'-vitro-N-nitrosoguanidine (NTG) mutagenesis [7].
• The appearance during anaerobiosis of spontaneous phoT phoB double mutants in a phoT background is described [8].

Other interactions of phoU

• By this test, TRF-2, TRF-3 and TRF-4 were identified with the pstA(=phoT), pstB and phoU genes, respectively [1].
• The pstC, pstB, and phoU gene products were identified as peripheral membrane proteins [9].

References