Poli^tm1Pjg

Nucleotide substitutions introduced into exon 4 produced D126A-E127A altered codons, and created a TseI restriction site for PCR genotyping. Expression studies showed that steady-state levels of mutant protein were approximately two-thirds of that observed for wild type. Analyses of wild-type and mutant POLI expressed in E. coli and human cells demonstrated that both enzymes bind to DNA and accumulate spontaneous replication foci proportionately to their expression levels, but the mutant POLI fails to extend DNA primers, i.e., it is catalytically inactive. (J:236535)