Disease relevance of orf2

• The derived amino acid sequences of orf2 and orf4 exhibit homology to Escherichia coli GalE and AdK, respectively [1].
• We therefore propose that orf2 and orf3 of the M-operon code for a structure-specific endonuclease (M-nuclease), which might be essential for phage multiplication [2].
• The lactococcal pyrKDbF operon is highly homologous to the corresponding part of the much-larger pyr operon of Bacillus subtilis. orf2, the pyrK homolog in B. subtilis, has also been shown to be necessary for pyrimidine biosynthesis (A. E. Kahler and R. L. Switzer, J. Bacteriol. 178:5013-5016, 1996) [3].
• The proteins encoded by orf1 and orf2 show the highest degree of similarity with similarly arranged peptide sequences translated from Corynebacterium glutamicum pXZ10142 and Mycobacterium fortuitum pAL5000 plasmids [4].
• However, the orf2 deduced peptide is 152 amino acids shorter than Rhizobium sp. N33 NodQ, and lacks the 3'-phosphoadenosine 5'-phosphosulphate-binding motif [5].

High impact information on orf2

• The sequence analysis of the 5'- and 3'-region of the gene cluster revealed three open reading frames (orf1, orf2, and orf3) which do not code for any ribosomal protein whose structure is known [6].
• Two of the open reading frames (orf2, orf6) code for proteins apparently carrying iron-sulphur clusters of the 4Fe/4S ferredoxin type [7].
• In addition an open reading frame (orf2), whose gene product is similar to bacterial regulatory (DNA-binding) proteins, was found just upstream from the coding region of the nitrilase [8].
• The complete nucleotide sequences of the tolQRA and oprL genes as well as the incomplete sequences of tolB and orf2 have been previously reported [9].
• Sequence similarity analysis has revealed that orf2, in the cell division 135-137 degrees region of the Bacillus subtilis (Bs) chromosome, is the probable homolog of Escherichia coli murB (encoding a reductase involved in peptidoglycan synthesis) [10].

Chemical compound and disease context of orf2

• The orf2-overexpressing E. coli also accumulate low concentrations of ethidium bromide, which was restored to wild type level in the presence of CCCP, an energy uncoupler altering the energy of the drug efflux pump [11].
• The orf2 conferred resistance to fluoroquinolones, tetraphenylphosphonium, streptomycin, and ethidium bromide when cloned and expressed in Escherichia coli KAM3, a strain lacking the multidrug efflux pump AcrAB [11].

Biological context of orf2

• Similarities between the products of P2 gene A, 186 gene A and orf2 and orf3 of Ec67 were also found [12].
• The region comprising orf1 and orf2 displayed a strikingly low G+C content and was present exclusively in C. glutamicum strains [13].
• As with nadB and orf2, mutations in nifS also resulted in a Nic-dependent phenotype [14].
• After the stop codon of orf2, a rho-independent terminator sequence was detected which is part of the P. aeruginosa PAO1 insertion element IS222 [15].
• The second and third genes encode proteins with similarities to zinc-finger proteins (orf2) and arginine kinases (orf3), respectively [16].

Associations of orf2 with chemical compounds

• These four genes and a homolog of the B. sphaericus bioW gene are arranged in a single operon in the order bioWAFDR and are followed by two additional genes, bioI and orf2. bioI and orf2 show no similarity to any other known biotin biosynthetic genes [17].

Other interactions of orf2

• Gene disruption experiments with the wild type proved that orf1 is essential for complementation, but inactivation of orf2 also resulted in a small but significant increase in fertility [13].
• A colony hybridization test was carried out against reference strains of E. coli representing serogroups O1 to O173 using O157 O-antigen synthesis genes (orf2-orf13) of E. coli O157 as probes [18].
• However, orf2 to orf11 and orf13 showed a much lower GC content of 30.0 to 39.4% [18].

References