Disease relevance of rIIB

• The DNA sequences of 185 independent spontaneous frameshift mutations in the rIIB gene of bacteriophage T4 are described [1].
• When the rII genes are first introduced into cells which had been previously infected by T4 phage deleted for these genes, the kinetics of synthesis of rIIA and rIIB RNA are rapid and identical [2].
• We have demonstrated the method by inserting a 203-bp DNA fragment from the lactose operon of Escherichia coli, into the dispensable region of the rIIB gene of T4 [3].

High impact information on rIIB

• Here, we show that ribosome frameshifting at a specific tryptophan codon during Trp-tRNA limitation accounts for suppression of a group of downstream frameshift alleles in the rIIB gene of bacteriophage T4 [4].
• Frameshift mutations were induced by proflavin in the rIIB gene of bacteriophage T4. rIIB DNA from each of 48 independent frameshifts was inserted into M13mp8 and sequenced [5].
• Two-thirds of the frameshifts (33/48) lie contiguous to one another in 10 base pairs of the rIIB sequence [5].
• The target for regA-mediated action overlaps the translational initiation domain of the rIIB messenger [6].
• Other phage-coded prereplicative proteins related to DNA replication and other phage functions such as the proteins coded by genes 32, 46, rIIA, and rIIB as well as many unidentified proteins were also consistently associated with the isolated fractions [7].

Biological context of rIIB

• The synthesis of the protein product of the rIIB cistron continues for several minutes after rIIA protein synthesis ceases (O'Farrell and Gold, 1973) [8].
• The two rII+ gene expressions might require different molar ratios of the rIIA and rIIB proteins [8].
• Frequency of rII(+) recombinants was measured in two-factor crosses of the type i x ets1, where ets1 designates an insertion in the rIIB gene carrying the cleavage site for SegC and i's are rIIB or rIIA point mutations located at various distances (12-2040 bp) from the ets1 site [9].
• Cloning the complete rIIB gene of bacteriophage T4 and some observations concerning its middle promoters [10].
• We have manipulated the dispensable region of the rIIB gene of bacteriophage T4 in order to study the generation of deletions involving direct repeats [11].

Associations of rIIB with chemical compounds

• In the in vitro translation system used in these studies, the rIIB protein synthesized at 25 degrees no longer contains the N-terminal formyl group whereas a large proportion of the formyl group is retained at 37 degrees [12].

Other interactions of rIIB

• Among the major proteins obtained are the DNA-dependent RNA polymerase of the host and the products of T4 genes rIIA, rIIB, and 32 (DNA-"unwinding" protein) [13].
• In addition, there are sequence similarities in the translation initiation regions of genes 44, 45, and rIIB, all of which are subject to regulation by regA protein [14].

References