The complete maps of BglII, SalI and XhoI restriction sites on T4 dC-DNA

Phage T4 DNA codes for two distinct 10-kDa proteins which strongly bind to RNA polymerase

Radioactive proteins have been synthesized in vitro from a coupled transcription-translation system primed with bacteriophage T4 DNA. The labeled proteins were chromatographed on RNA polymerase-Sepharose affinity columns in order to identify a protein which comigrates with the 10-kDa anti-sigma subunit of T4-modified RNA polymerase. When we primed the in vitro system with specific restriction fragments of T4 DNA, we found that there seemed to be two widely separated genes which code for this protein. The products of these two genes were compared by two-dimensional electrophoresis; they were found to have different charges, even though they had the same molecular weight and strong affinity for RNA polymerase. One of these proteins exists in a form which has the same charge as the 10-kDa subunit isolated from purified T4-modified RNA polymerase. We report a preliminary mapping experiment within the 22.5-kb fragment harboring this gene.

A physical map of bacteriophage T4 including the positions of strong promoters and terminators recognized in vitro

We present a linearized physical map of the genome of bacteriophage T4. This map contains the cleavage sites for restriction enzymes SmaI, KpnI, SalI, BglII, XhoI, XbaI, ClaI , HaeII, EcoRI, and EcoRV . It also contains about 200 TaqI sites. The promoter sites recognized in vitro and a number of rho independent terminators have also been mapped.

Map of restriction sites on bacteriophage T4 cytosine-containing DNA for endonucleases bamHI, BglII, KpnI, PvuI, SalI, and XbaI

A complete map of the cleavage sites of restriction endonucleases BamHI, BglII, KpnI, PvuI, SalI, and XbaI was determined for the cytosine-containing DNA of a bacteriophage T4 alc mutant. The 56 sequence-specific sites were assigned map coordinates based on a least-squares analysis of measured fragment lengths. Altogether, the lengths of 118 fragments from single and double enzyme digestions were measured by electrophoresis of the fragments in agarose gels. DNA fragments of known sequence or DNA fragments calibrated with fragments of known sequence were used as standards. The greatest deviation between an experimentally measured fragment length and its computed map coordinates was 3.0%; the average deviation was 0.8%. The total length of the wild-type T4 genome was calculated to be 166,200 base pairs.

Correlation between genetic map and map of cleavage sites for sequence-specific endonucleases SalI, KpnI, BglI, and BamHI in bacteriophage T4 cytosine-containing DNA

Cleavage sites for SalI, KpnI, BglI, and BamHI in cytosine-containing DNA from T4 alc10(alc) nd28(denA) D2a2(denB) amE51x5(56) amN55x5(42) have been mapped relative to each other, and the positions of deletions sa delta 9 (D1-stp), r1589(rII), del(39-56)12, and tk2(rI-tk) relative to these cleavage sites have been determined. Based on these analyses, a physical map of the T4 genome containing 166 kilobase pairs has been constructed.

A restriction map of the bacteriophage T4 genome

We report a detailed restriction map of the bacteriophage T4 genome and the alignment of this map with the genetic map. The sites cut by the enzymes Bg/II, XhoI, KpnI, SalI, PstI, EcoRI and HindIII have been localized. Several novel approaches including two-dimensional (double restriction) electrophoretic separations were used.