Intergeneric protoplast fusion between Escherichia coli HB101 with pBR322 carrying the cloned o-(carboxymethyl)cellulase (CMCase) gene of Ruminococcus albus (Pro Leu Ap Km) and an anaerobic mutant strain, FEM29 (Trp His Ap Km), with dehydrodivanillin-degrading activity was performed in the presence of 40% polyvinyl alcohol 300 under aerobic and anaerobic conditions to transfer the cloned cellul...

Although heat-stable (ST) and heat-labile (LT) enterotoxins produced by enterotoxigenic Escherichia coli (ETEC) have been documented as important factors associated with diarrheal diseases, investigations assessing the contributions of individual enterotoxins to the pathogenesis of E. coli infection have been limited. To address the individual roles of enterotoxins in the diarrheal disease caus...

A previously cloned 503-base pair (bp) EcoRI segment of genomic DNA from Xenopus laevis selected for enhancement of replication of its vector plasmid was moved to the EcoRI site of pBR322. This plasmid designated pJCC31 and five other clones, which were made by cleaving the 503-bp segment in relation to a dispersed repeated sequence and subcloning, were compared with pBR322 for replication by m...

The behavior in Saccharomyces cerevisiae of plasmid pYTE1, which contains yeast tyrosine-inserting ochre suppressor SUP4.o, a 4-kilobase EcoRI fragment of yeast 2muDNA, and the bacterial plasmid pBR322, has been studied. Selection of yeast transformants was by suppression of multiple ochre mutations. About 10(3) to 10(4) transformants per microgram of pYTE1 dfeoxyribonucleic acid were obtained....

Berenil, a minor groove DNA binding molecule, has been extensively used in veterinary medicine. Modeling studies have suggested that berenil binds to A/T rich regions on the DNA and the product of this interaction causes the formation of crosslinks between opposite DNA strands. These crosslinks could potentially inhibit fundamental biological processes including transcription and DNA replicatio...

Steady-state parameters governing cleavage of pBR322 DNA by EcoRI endonuclease are highly sensitive to ionic environment, with K(m) and k(cat) increasing 1,000-fold and 15-fold, respectively, when ionic strength is increased from 0.059 to 0.23 M. By contrast, pre-steady-state analysis has shown that recognition, as well as first and second strand cleavage events that occur once the enzyme has a...

An in vitro assay for adeno-associated virus (AAV) DNA replication has been developed. The substrate is a plasmid containing the duplex form of AAV DNA in pBR322. The AAV insert is excised or rescued from the plasmid by extracts of uninfected cells. Replication was assayed by production of full-length excised AAV DNA resistant to Dpn I digestion. The following results were obtained. (i) Only ex...

We have taken a new approach to identify and fine map previously undescribed herpes simplex virus (HSV) functions. In experiments described in this report the antibiotic coumermycin A1 was used to select two HSV type 1 BamHI fragments cloned in pBR322 that confer partial resistance to drug-susceptible Escherichia coli. The genes encoding these HSV functions have been designated cour-1 and cour-...

The structural genes of ADPglucose pyrophosphorylase (glgC) and glycogen synthase (glgA) from Salmonella typhimurium LT2 were cloned on a 5.8-kilobase-pair insert in the SalI site of pBR322. A single strand specific radioactive probe containing the N terminus of the Escherichia coli K-12 glgC gene in M13mp8 was used to hybridize against a S. typhimurium genomic library in lambda 1059. DNA from ...

Cleavage of pBR322 DNA I by the restriction endonuclease HinfI is preferentially inhibited at specific HinfI cleavage sites. These sites in pBR322 DNA I have been identified and ordered with respect to the frequency with which they are cleaved. The HinfI site most resistant to cleavage in pBR322 DNA I is unique in that runs of G-C base pairs are immediately adjacent on both sites. Two different...