The large Rep proteins, p68 and p78, function as master controllers of the adeno-associated virus type 2 (AAV2) life cycle, involved in transcriptional control, in latency, in rescue, and in viral DNA replication. The p5 promoter may be the nucleic acid complement to the large Rep proteins. It drives expression of the large Rep proteins, it undergoes autoregulation by Rep, it undergoes inductio...

Replication of staphylococcal multiresistance plasmid pSK41 is negatively regulated by the antisense transcript RNAI. pSK41 minireplicons bearing rnaI promoter (PrnaI) mutations exhibited dramatic increases in copy number, approximately 40-fold higher than the copy number for the wild-type replicon. The effects of RNAI mutations on expression of the replication initiator protein (Rep) were eval...

The replication-associated (Rep) protein of porcine circovirus (PCV) was suggested to play an essential role in the replication and translation of viral DNA. In this study, one monoclonal antibody (mAb) specific for Rep protein of porcine circovirus type 1 (PCV1), two mAbs against Rep protein of porcine circovirus type 2 (PCV2), and five mAbs to both Rep protein of PCV1 and PCV2 were generated ...

The effects of recombinant human erythropoietin (rEp) on murine hematopoietic progenitors were studied using a serum-free culture. A high concentration of rEp stimulated the formation of mixed erythroid-megakaryocyte colonies (EM colonies) and blast cell colonies, as well as erythroid colonies, erythroid bursts, and megakaryocyte colonies from normal mouse bone marrow cells. Direct effects of r...

The cryptic multicopy plasmid pGA1 (4,826 bp) from Corynebacterium glutamicum LP-6 belongs to the fifth group of rolling-circle-replicating plasmids. A determinant, which negatively controls pGA1 replication, was localized in the leader region of the rep gene coding for the initiator of plasmid replication. This region, when cloned into the compatible vector pEC6, was found to cause decrease of...

DNA helicases catalyze the essential process of unwinding duplex DNA to form the single-stranded DNA intermediates required for DNA metabolic processes including replication, recombination, and repair. Most cells, possibly all, encode multiple helicases that function selectively in different processes, although some helicases can complement each other in vivo. Thus, although Escherichia coli ca...

The roles of UvrD and Rep DNA helicases of Escherichia coli are not yet fully understood. In particular, the reason for rep uvrD double mutant lethality remains obscure. We reported earlier that mutations in recF, recO or recR genes suppress the lethality of uvrD rep, and proposed that an essential activity common to UvrD and Rep is either to participate in the removal of toxic recombination in...