Transcription direction

Dalby, B., and Glover, D. M. (1992). 3 non-translated sequences in Drosophila cyclin B transcripts direct posterior pole accumulation late in oogenesis and perinuclear association in syncitial embryos. Development 115 989-997. 

Three of the MBD family members, namely MeCP2, MBDl, and MBD2, have been shown to act as transcriptional repressors in vitro and in cell culture assays in vivo [86-89,75,76]. Initially it was proposed that methyl-CpG binding proteins inhibit transcription directly, by binding to methylated DNA and blocking the access of transcription factors to their sites at gene promoters. It was soon... 

Figure 5 Genes involved in carbomycin biosynthesis. (A) Structure of the carbomycin biosynthetic cluster of S. thermotolerans. Locations and transcriptional directions of nine carbomycin genes identified by the researchers at Eli Lilly and our group are illustrated schematically. (B) List of the carbomycin biosynthetic genes and the functions identified.

Chang, L. S. and Shenk, T. (1990). The adenovirus DNA-binding protein stimulates the rate of transcription directed by adenovirus and adeno-associated virus promoters. J. Virol. 64, 2103-2109. 

Fig. 12.9 Indirect control of transcription by cyclin-Cdks involves interactions of transcription fector E2F with the tumour suppressors p53 and pRB. Cyclin D- and cyclin E-associated kinases phosphorylate pRB and lift the biock of transcription. Appropriate changes of the phosphorylation state of p53 improve the specificity of DNA binding arxj promote the transcriptional activity of E2F. This effect is amplified by phosphorylation of p53 by cyiin A-Cdkl. (Cyclin H/Cdk7/CAK and cyclin C/Cdk8 complexes can activate transcription directly, by association with the basal transcription machinery and phosphorylation of RNA polymerase II, Pol II see also Chapters 9 and 10).

Fig. 12.1. Relative sizes of mitochondrial and chloroplast chromosomes and location of protein structural genes. The figure was constructed from published data [5,15,17,22,26-28]. The structural genes are marked by wide sections. Black areas code for proteins. White areas are introns. 0x1, OxII and OxIII are subunits I, II and III of cytochrome c oxidase. Cyt b, cytochrome b. Fo and Fo, are subunits 6 and 9 of the proton ATPase complex. In the chloroplast chromosome the arrows indicate the transcription direction and the size of the transcripts. CF,a, CFj/8, CFjc and CFoIII are subunits a, /S, t and III of the chloroplast proton ATPase complex [30]. PSII5], PSII44, and PSII34 are subunits of photosystem II reaction center with the corresponding molecular weights of 51000, 44000 and 34000. PSI70 is subunit I of photosystem I reaction center. Cyt /is cytochrome/ cyt is cytochrome b and b -flV is subunit IV of cytochrome b(,-f complex.

RNA polymerase III promoters differ significantly from RNA polymerase II promoters in that they are located downstream from the transcription start site and within the transcribed segment of the DNA. For example, in the 5S RNA gene of the South African toad Xenopus laevis) the promoter is between 45 and 95 nucleotides downstream from the start point. Thus, the binding sites on RNA polymerase III are reversed with respect to the transcription direction, as compared with RNA polymerase II. That is, RNA polymerase II reaches forward to find the start point, and RNA polymerase III reaches backward. In fact, RNA polymerases can slide in either direction along a DNA template however, they can only synthesize RNA molecules in a 5 3 direction. 

Kinoshita K, Harigai M, Fagarasan S, Muramatsu M, Honjo T A hallmark of active class switch recombination transcripts directed by I promoters on looped-out circular DNAs. Proc Natl Acad Sci USA 2001 98 12620-12623. 

Kaebemick, M. et al.. Multiple alternate transcripts direct the biosynthesis of microcystin, a cyanobacterial nonribosomal peptide, Appl. Environ. Microbiol, 68, 449, 2002. 

Zhou H, Glimcher LH (1995) Human MHC class II gene transcription directed by the carboxyl terminus of CIITA, one of the defective genes in type II MHC combined immune deficiency. Immunity 2 545-553... 

The choice of a particular enzyme depends on the type of vector and the nature of the insert. Use an enzyme that cuts wifliin the multiple cloning site of the vector distal to the insert from the T7 promoter, to produce a linear molecule containing vector DNA, T7 promoter, insert, and cleavage site in the correct transcription direction. 

Figure 3.117 Oiganization of the gene cluster for pimaricin biosynthesis. The transcriptional direction and tiie relative sizes of the predicted orfs are indicated by pointed boxes, orfs corresponding to the PKS are indicated in color. Additional orfs of putative pimaricin tailoring, regulation, and resistance functions are indicated in gray. The 3P end of an unidentified orf (orfX) is indicated in white. Only BamHI restriction sites (B) are indicated. With permission from Aparicio et al. (2000). Copyright 2000, Elsevier.

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