Evidence that there are two basically different types of protein present in calf thymus, which stimulate the DNA dependent RNA polymerase reaction

Size of the unwound region of DNA in Escherichia coli RNA polymerase and calf thymus RNA polymerase II ternary complexes.

Calf thymus polymerase.

The term polymerase has been applied to the deoxyribonucleoside triphosphate-polymerizing enzyme isolated from Escherichia coli (1). Enzymes with similar activity have been purified from regenerating rat liver (2) and calf thymus gland (3). An ample and varied supply of such polymerases is desirable for studies on the mechanism of deoxyribonucleic acid synthesis. The present work describes a pa...

Four different DNA helicases from calf thymus.

Using a strand displacement assay we have followed DNA helicase activities during the simultaneous isolation of several enzymes from calf thymus such as DNA polymerases alpha, delta, and epsilon, proliferating cell nuclear antigen, and replication factor A. Thus we were able to discriminate and isolate four different DNA helicases called A, B, C, and D. DNA helicase A is identical with the enzy...

DNA polymerase lambda from calf thymus preferentially replicates damaged DNA.

A new gene (POLL), has been identified encoding the novel DNA polymerase lambda and mapped to mouse chromosome 19 and at human chromosome 10. DNA polymerase lambda contains all the critical residues involved in DNA binding, nucleotide binding, nucleotide selection, and catalysis of DNA polymerization and has been assigned to family X based on sequence homology with polymerase beta, lambda, mu, ...

Purification of RNA polymerase IIO from calf thymus.

Three subspecies of RNA polymerase II, designated IIO, IIA, and IIB, have been described in calf thymus and shown to differ in the apparent molecular weight of their largest subunits, designated IIo, IIa, and IIb, respectively. The objective of this study was to develop a procedure for the purification of RNA polymerase IIO. This form of the enzyme predominates in vivo and is responsible for th...