title: Single-stranded DNA structure and DNA polymerase activity in the presence of nucleic acid helix-unwinding proteins from calf thymus.
abstract: In the preceding articles we have described the isolation and some of the properties of two calf thymus proteins which bind selectively to single-stranded DNA and which appear analogous to previously isolated prokaryotic DNA-unwinding proteins. In the present work we demonstrate two further points of analogy. First, both the calf UP1 and the high salt eluting proteins form protein-rich complexes with single-stranded DNA, and hold this DNA in a rigid, extended conformation. Second, these proteins stimulate the calf thymus DNA polymerase-alpha; phage T4 gene 32-protein does not. The stimulation of a homologous DNA polymerase is characteristic of several prokaryotic DNA-unwinding proteins and is assumed to reflect their in vivo role in DNA synthesis.
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA / Q000378:metabolism; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000096:biosynthesis; D003852:Deoxyribonucleoproteins / Q000378:metabolism*; D008854:Microscopy, Electron; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D009698:Nucleoproteins / Q000378:metabolism*; D011487:Protein Conformation; D013950:Thymus Gland / Q000201:enzymology*
chemical_list: D004277:DNA, Single-Stranded; D003852:Deoxyribonucleoproteins; D009698:Nucleoproteins; D004247:DNA; D004254:DNA Nucleotidyltransferases