UV-damaged DNA-binding activity (UV-DDB) is deficient in some xeroderma pigmentosum group E individuals due to mutation of the p48 gene, but its role in DNA repair has been obscure. We found that UV-DDB is also deficient in cell lines and primary tissues from rodents. Transfection of p48 conferred UV-DDB to hamster cells, and enhanced removal of cyclobutane pyrimidine dimers (CPDs) from genomic...

The human UV-damaged-DNA binding protein DDB has been linked to the repair deficiency disease xeroderma pigmentosum group E (XP-E), because a subset of XP-E patients lack the damaged-DNA binding function of DDB. Moreover, the microinjection of purified DDB complements the repair deficiency in XP-E cells lacking DDB. Two naturally occurring XP-E mutations of DDB, 82TO and 2RO, have been characte...

E.coli 4.5S RNA is homologous to domain IV of eukaryotic SPR7S RNA, the RNA component of the signal recognition particle. The 4.5S RNA is associated in vivo with a 48kD protein (P48), which is homologous to a protein component of the signal recognition particle, SRP54. In addition to secondary structural features, a number of nucleotides are conserved between the 4.5S RNA and domain IV of all o...

CD56(high) acute myeloid leukemias (AMLs) have a poor prognosis, but it has been unclear how CD56 expression is controlled and how it relates to clinical aggressiveness. We show that CD56 expression on AML cells correlates with an abnormal expression pattern of runt-related transcription factor 1 (RUNX1) isoforms. Whereas full-length p48 RUNX1 (p48) up-regulated CD56 in AML cells, 3 previously ...

In human cells, efficient global genomic repair of DNA damage induced by ultraviolet radiation requires the p53 tumor suppressor, but the mechanism has been unclear. The p48 gene is required for expression of an ultraviolet radiation-damaged DNA binding activity and is disrupted by mutations in the subset of xeroderma pigmentosum group E cells that lack this activity. Here, we show that p48 mRN...

This study determined the conservation and protective efficacy of a 48 kDa nontypable Haemophilus influenzae (NTHi) protein (P48). This protein was highly conserved across the strains of NTHi examined and mucosal immunization with recombinant P48 (rP48) significantly reduced the numbers of viable NTHi recovered from the lung following challenge. rP48 induced predominantly an IgG2a antibody resp...

Damaged DNA-binding protein, DDB, is a heterodimer of p127 and p48 with a high specificity for binding to several types of DNA damage. Mutations in the p48 gene that cause the loss of DDB activity were found in a subset of xeroderma pigmentosum complementation group E (XP-E) patients and have linked to the deficiency in global genomic repair of cyclobutane pyrimidine dimers (CPDs) in these cell...

Although p48 is the most conserved subunit of mammalian DNA polymerase alpha-primase (pol-prim), the polypeptide is the major species-specific factor for mouse polyomavirus (PyV) DNA replication. Human and murine p48 contain two regions (A and B) that show significantly lower homology than the rest of the protein. Chimerical human-murine p48 was prepared and coexpressed with three wild-type sub...

DNA replication in all organisms requires polymerases to synthesize copies of the genome. DNA polymerases are unable to function on a bare template and require a primer. Primases are crucial RNA polymerases that perform the initial de novo synthesis, generating the first 8-10 nucleotides of the primer. Although structures of archaeal and bacterial primases have provided insights into general pr...

The monoclonal antibody (mAb) 21A6, which specifically inhibits yeast DNA primase activity, has been used to verify whether only one of the two polypeptides of heterodimeric DNA primase (48 and 58 kDa) was responsible for DNA primase function in vitro. Immunoaffinity chromatography of a crude extract from cells of Saccharomyces cerevisiae on a mAb 21A6 protein A-Sepharose 6B column allowed the ...