Disease relevance of 2.5

• Two proteins encoded by bacteriophage T7, the gene 2.5 single-stranded DNA binding protein and the gene 4 helicase, mediate homologous DNA strand exchange [1].
• After infection of E. coli with T7 delta 2.5, host DNA synthesis is shut off, and phage DNA synthesis is reduced to < 1% of phage DNA synthesis in wild-type T7-infected E. coli cells as measured by incorporation of [3H]thymidine [2].
• T7 phages that contain null mutants of gene 2.5 were constructed by homologous recombination [2].

High impact information on 2.5

• Gene 2.5 protein stimulates homologous base pairing of two DNA molecules containing complementary single-stranded regions [1].
• The defects in growth and DNA replication are overcome by wild-type gene 2.5 protein expressed from a plasmid harboring the T7 gene 2.5 [2].
• We have identified a single amino acid residue in gene 2.5 protein, arginine 82, that is critical for its DNA annealing activity [3].
• In bacteriophage T7-infected cells, the product of viral gene 2.5, a single-stranded DNA-binding protein, performs this function [3].
• Gene 2.5 of bacteriophage T7 is an essential gene that encodes a single-stranded DNA-binding protein (gp2.5) [4].

Biological context of 2.5

• 5. By screening a library of randomly mutated plasmids encoding gene 2.5, we identified 20 different single amino acid alterations in gene 2.5 protein that are lethal in vivo [5].
• A truncated gene 2.5 protein (GP2.5-delta 21C) was constructed by in vitro mutagenesis and lacks the 21 carboxyl-terminal amino acids found in wild-type gene 2.5 protein, 15 of which are acidic [6].
• 5. Neither of the suppressor mutations for the op1 mutation suppressed other gene 2.5 mutations, ts2.5 and am2.5-2 [7].

Associations of 2.5 with chemical compounds

• Whereas transcription buffer containing 2.0-2.5 mM Mn(2+) supports T7 RNA polymerase-mediated insertion of 8-N(3)AMP into RNA, a mixture of 2.5 mM Mn(2+) and 2.5 mM Mg(2+) further improves the yield of 8-N(3)AMP-containing transcript [8].
• By 5 min after infection the activity of alc mutants was 1.5 to 2.5 times greater than that of the wild type on various cytosine-containing DNA templates, whereas there was little or no difference in activity on T4 HMdC-DNA, in agreement with the in vivo specificity [9].

Analytical, diagnostic and therapeutic context of 2.5

• GP2.5-delta 21C has been purified to apparent homogeneity from cells overexpressing its cloned gene and has a conformation that differs from that of the wild-type gene 2.5 protein as judged by its circular dichroism spectra [6].
• Gene 2.5 protein-R82C condenses single-stranded M13 DNA in a manner similar to wild-type protein when viewed by electron microscopy [3].

References