Operon genes

Jocobi A, Rossmann R, Bock A. 1992. The hyp operon gene products are required for the maturation of catalytically active hydrogenase isoenzymes in Escherichia coli. Arch Microbiol 158 444-51. 

FIGURE 28-5 Representative prokaryotic operon. Genes A, B, and C are transcribed on one polycistronic mRNA. Typical regulatory sequences include binding sites for proteins that either activate or repress transcription from the promoter. 

As indicated in Fig. 28-11, the chromosome can be divided into four major operons, the short one that produces repressor, and the early left, early right, and late operons. The early operons code largely for replication and recombination enzymes and control proteins. The late operon is concerned with production of proteins needed for assembly of the virus particles and must be transcribed at an even higher rate hence the need for the product of gene Q. Within the late operon, genes A to F are involved in packaging of K DNA and in formation of heads, while genes S to / are... 

The CAP-cAMP complex stimulates the initiation of transcription by approximately a factor of 50. A major factor in this stimulation is the recruitment of RNA polymerase to promoters to which CAP is bound. Studies have been undertaken to localize the surfaces on CAP and on the a subunit of RNA polymerase that participate in these interactions (Figure 3111). These energetically favorable protein-protein contacts increase the likelihood that transcription will be initiated at sites to which the CAP-cAMP complex is bound. Thus, in regard to the lac operon, gene expression is maximal when the binding of allolactose relieves the inhibition by the lac repressor, and the CAP-cAMP complex stimulates the binding of RNA polymerase. 

The striking conservation of the str operon gene order across domain boundaries (i.e., in the bacterium E. coli and the archaeon M. vannielii) suggests that the (str operon)-... 

Our understanding of Zn(II) homeostasis in E. coli is far from complete. It is clear that intracellular Zn(II) transport in bacteria is different that the transport of other metal ions, since none of the known Zn(II) proteins have the genes for transport proteins on the same operon/gene cluster. In addition, DNA microarrays have failed to identify a single Zn(II)-metallochaperone candidate. It is possible that Zn(II)-metallochaperones are not Zn(II)-responsive, and therefore would not be up- or down-regulated by the presence/absence of Zn(II). 

Panina, L.I. et al. (1983) Cloning the operon genes of riboflavin biosynthesis in Bacillus suhtilis on plasmid vector pBR322 in Escherichia coli. Genetika,... 

PUF OPERON GENE ORGANIZATION AND RESTRICTION MAP. The Asp 718 and Nru 1 restriction sites shown indicate the region deleted from the genome of the photosynthetic minus deletion mutant PUFALMX21. The 5.3 kb shown is sufficient to restore the PS phenotype in trans. 

Chan, E.C., Tsai, H.L., Chen, S.L., and Mou, D.G. (1993) Amplification of the tryptophan operon gene in Escherichia coli chromosome to increase L-tryptophan biosynthesis. Appl Microbiol Biotechnol, 40, 301-305. 

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