Base excision repair (BER) is a DNA repair pathway designed to correct small base lesions in genomic DNA. While DNA polymerase beta (pol b) is known to be the main polymerase in the BER pathway, various studies have implicated other DNA polymerases in back-up roles. One such polymerase, DNA polymerase lambda (pol l), was shown to be important in BER of oxidative DNA damage. To further explore r...

A new form of DNA polymerase III, termed Pol III star (Pol III(*)), has been purified to homogeneity from Escherichia coli. Pol III(*) is temperature sensitive when isolated from a thermo-sensitive dnaE mutant, as had been described for Pol III. Pol III(*) and Pol III are separable by gel filtration. Pol III(*) utilizes a duplex template containing short gaps with the same catalytic properties ...

S1 Fig. Analysis of Pol II density across the transcriptional units following gene activation. ChIP density estimates of Pol II density during the indicated period of maximal, activated expression following α1aAR stimulation. Primer locations associated with 5’ end of upstream primer relative to the transcription start site (i.e. TSS bp is 1). (A) Pol II density on Fos, expressed as the number ...

GATA-1 is an erythroid activator that binds b-globin gene promoters and DNase I hypersensitive sites (HSs) of the b-globin locus control region (LCR). We investigated the direct role of GATA-1 interaction at the LCR HS2 enhancer by mutating its binding sites within minichromosomes in erythroid cells. Loss of GATA-1 in HS2 did not compromise interaction of NF-E2, a second activator that binds to...

The replisome catalyses DNA synthesis at a DNA replication fork. The molecular behaviour of the individual replisomes, and therefore the dynamics of replication fork movements, in growing Escherichia coli cells remains unknown. DNA combing enables a single-molecule approach to measuring the speed of replication fork progression in cells pulse-labelled with thymidine analogues. We constructed a ...

Proliferating cell nuclear antigen (PCNA) has been shown to interact with a variety of DNA polymerases (pol) such as pol delta, pol epsilon, pol iota, pol kappa, pol eta, and pol beta. Here we show that PCNA directly interacts with the newly discovered pol lambda cloned from human cells. This interaction stabilizes the binding of pol lambda to the primer template, thus increasing its affinity f...

Nuclear multisubunit RNA polymerases IV and V (Pol IV and Pol V) evolved in plants as specialized forms of Pol II. Their functions are best understood in the context of RNA-directed DNA methylation (RdDM), a process in which Pol IV-dependent 24 nt siRNAs direct the de novo cytosine methylation of regions transcribed by Pol V. Pol V has additional functions, independent of Pol IV and 24 nt siRNA...

Founded by the World Me te o ro log i cal Or ga ni za tion (WMO) and the United Na tions En vi ron ment Programme (UNEP) in 1988, the In ter gov ern men tal Panel on Cli mate Change (IPCC) is en gaged in a unique sci en tific as sess ment pro cess. Not only is the IPCC ex plic itly tied to the United Na tions Frame work Con ven tion on Cli mate Change (UNFCCC) as its pol icy au di ence, but it ...

The dnaN159 allele encodes a temperature-sensitive mutant form of the β sliding clamp (β159). SOS-induced levels of DNA polymerase IV (Pol IV) confer UV sensitivity upon the dnaN159 strain, while levels of Pol IV ∼4-fold higher than those induced by the SOS response severely impede its growth. Here, we used mutations in Pol IV that disrupted specific interactions with the β clamp to test our hy...