| host factors involved in the growth of microvirid phage alpha 3. | host factors involed in the growth of microvirid phage alpha3 were determined using various replication mutants of escherichia coli. the viral multiplication was dependent on functional products of dnae, dnaf(nrda), dnag, and dnaz genes. host functions directed by dnaa, so-alled dnah, dnai, and dnap genes were dispensable for the viral growth. in contrast with phiz174 and g4, alpha3 would grow sufficiently in dnab and dnac(d) mutants. the viral growth was not significantly affected by host polat ... | 1978 | 153669 |
| synthesis of alpha3 phage dna in replication mutants of escherichia coli. | host functions for dna replication of bacteriophage alpha3, a representative of group a microvirid phages, were studied using dna and rep mutants of escherichia coli. in dna+ cells, conversion of phage alpha3 single-stranded dna (ss) into the double-stranded replicative form (rf) was insensitive to 30--150 microgram/ml of chloramphenicol, 200 microgram/ml of rifampicin, 50 microgram/ml of nalidixic acid, or 200 microgram/ml of novobiocin. at 43 degrees c, synthesis of the parental rf was inhibit ... | 1978 | 341979 |
| novel replication mutant of microvirid phage alpha 3 deleted in the complementary strand origin. | the bacteriophage alpha 3 origin of complementary strand dna synthesis (-ori) contains two potential secondary loop structures (i and ii), which have been implicated as direct recognition sites for host escherichia coli dnag protein. to elucidate to what extent such structures are essential, we introduced a nucleotide deletion within the -ori region, by nuclease digestion of alpha 3 replicative form dna. a mutant, delb, thus constructed had a 121 nucleotide deletion within the -ori region and wa ... | 1990 | 2325622 |
| mutational analysis of the bacteriophage alpha 3 origin of complementary dna synthesis: in vivo properties of mutants. | bacteriophage alpha 3 origin of complementary strand dna synthesis contains two potential secondary loop structures, i and ii, which have been implicated in direct recognition sites for host escherichia coli dnag protein. to elucidate the function of the hairpin loops, we have introduced point mutations within the stem of the hairpin ii so as to disturb its base-pairings. a mutant, oriaa, which had two point mutations in the region, formed minute plaques on e. coli host cells and its mean burst ... | 1989 | 2930780 |
| function and structure of microvirid phage alpha 3 genome. ii. isolation and properties of various mutants of alpha 3. | various mutants were isolated from a microvirid (isometric single-stranded dna) phage alpha 3, by mutagenesis with hydroxylamine or nitrous acid. they were divided into eight complementation groups, and mainly by genetic crosses the gene alignment was determined as -a-b-c'-d-j'-f-g-h-. except for groups c' and j', each defective gene product was clearly discerned in electropherograms of proteins extracted from the phage-infected suppressor-negative (su-) escherichia coli. only gene a mutants abo ... | 1984 | 6238630 |
| initiation of dna replication by the dnag protein. | highly purified preparations of dnag protein from escherichia coli prime minus strand synthesis of phage alpha 3 dna in vitro. this protein synthesizes primer oligonucleotides which may be composed of ribonucleotide or deoxyribonucleotide moieties or both. the presence of deoxyribonucleotide moieties in the chain limits primer chain length; this effect occurs even when ribonucleoside triphosphates are included in the priming reaction. the dnag protein can use adp in place of atp. primer formatio ... | 1980 | 6985903 |
| properties of the bacteriophage alpha 3 mutants with deletion and/or insertion in the complementary strand origin. | bacteriophage alpha 3 origin of complementary strand dna synthesis (-ori) contains two potential secondary loop structures (i and ii), which have been implicated in direct recognition sites for host escherichia coli dnag protein. we have introduced nucleotide deletion or insertion within the -ori region, by nuclease digestion and polymerase treatment of alpha 3 replicative form dna. deletion mutants (delo) showing the following in vivo properties were isolated: minute plaque size, longer latent ... | 1990 | 2137016 |
| nucleotide sequence of the genome of the bacteriophage alpha 3: interrelationship of the genome structure and the gene products with those of the phages, phi x174, g4 and phi k. | the complete nucleotide sequence of the genome of the circular single-stranded dna (isometric) phage alpha 3 has been determined and compared with that of the related phages phi x174 and g4. the alpha 3 genome consists of 6087 nucleotides, which is 701 nucleotides longer than the nucleotide sequence of the phi x174 genome and 510 nucleotides more than that of the g4 genome. the results demonstrated that the three phage species have 11 homologous genes (a, a*, b, c, k, d, e, j, f, g and h), the o ... | 1992 | 1532908 |
| structural studies of bacteriophage alpha3 assembly. | bacteriophage alpha3 is a member of the microviridae, a family of small, single-stranded, icosahedral phages that include phix174. these viruses have an ssdna genome associated with approximately 12 copies of an h pilot protein and 60 copies of a small j dna-binding protein. the surrounding capsid consists of 60 f coat proteins decorated with 12 pentameric spikes of g protein. assembly proceeds via a 108s empty procapsid that requires the external d and internal b scaffolding proteins for its fo ... | 2003 | 12473449 |
| isolation and some properties of bacteriophage alpha3 gene j mutant. | to elucidate the in vivo function of the j gene of microvirid (isometric) phages, we isolated several strains carrying a double mutation in j and h genes from phage alpha3 and then constructed single mutants each having an amber codon in the j gene. the j mutants could not multiply in suppressor-less hosts and were deficient in single-stranded progeny dna synthesis. nucleotide sequences of the wild-type and mutant alpha# j genes were analyzed to determine the mutation sites. the amino acid seque ... | 1984 | 6088949 |
| function and structure of microvirid phage alpha 3 genome. dna sequence of h gene and properties of missense h mutant. | the nucleotide sequence of wild-type alpha 3 h gene and its surrounding region was determined and compared with those of phi x174 and g4. the corresponding dna regions in double mutants amjh22, amjh69 and amjh76 were also sequenced and their missense mutation sites located. a phage strain missh22 having a single missense mutation in gene h was constructed by replacing the j region of amjh22 in vitro with the wild-type dna. like amjh22, the missense mutant coded for h protein with aberrant electr ... | 1985 | 2988629 |