Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q02556 (DNA-binding domain)
 6,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The two human proteins Ki-1/57 and CGI-55 have highly similar amino acid sequences but their functions are unknown. We analyzed them by yeast two-hybrid screens and found that they interact with the C-terminal region of the human chromatin-remodeling factor CHD-3 (chromo-helicase-DNA-binding domain protein-3). The interaction of CGI-55 and CHD-3 could be confirmed in vitro and in vivo by co-immunoprecipitations from Sf9 insect cells. Mapping showed that CGI-55 interacts with CHD-3 via two regions at its N- and C-terminals. The CGI-55 and Ki-1/57 mRNAs show highest expression in muscle, colon and kidney. A CGI55-GFP fusion protein was localized in the cytoplasm, nucleus and perinuclear regions of HeLa cells. These data suggest the possibility that CGI-55 and Ki-1/57 might be involved in nuclear functions like the remodeling of chromatin.
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PMID:Characterization of a new family of proteins that interact with the C-terminal region of the chromatin-remodeling factor CHD-3. 1250 51

The E1 helicase of papillomaviruses is required for replication of the viral double-stranded DNA genome, in conjunction with cellular factors. DNA replication is initiated at the viral origin by the assembly of E1 monomers into oligomeric complexes that have unwinding activity. In vivo, this process is catalyzed by the viral E2 protein, which recruits E1 specifically at the origin. For bovine papillomavirus (BPV) E1 a minimal DNA-binding domain (DBD) has been identified N-terminal to the enzymatic domain. In this study, we characterized the DBD of human papillomavirus 11 (HPV11), HPV18, and BPV E1 using a quantitative DNA binding assay based on fluorescence anisotropy. We found that the HPV11 DBD binds DNA with an affinity and sequence requirement comparable to those of the analogous domain of BPV but that the HPV18 DBD has a higher affinity for nonspecific DNA. By comparing the DNA-binding properties of a dimerization-defective protein to those of the wild type, we provide evidence that dimerization of the HPV11 DBD occurs only on two appropriately positioned E1 binding-sites and contributes approximately a 10-fold increase in binding affinity. In contrast, the HPV11 E1 helicase purified as preformed hexamers binds DNA with little sequence specificity, similarly to a dimerization-defective DBD. Finally, we show that the amino acid substitution that prevents dimerization reduces the ability of a longer E1 protein to bind to the origin in vitro and to support transient HPV DNA replication in vivo, but has little effect on its ATPase activity or ability to oligomerize into hexamers. These results are discussed in light of a model of the assembly of replication-competent double hexameric E1 complexes at the origin.
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PMID:Characterization of the minimal DNA binding domain of the human papillomavirus e1 helicase: fluorescence anisotropy studies and characterization of a dimerization-defective mutant protein. 1269 20

Bloom syndrome protein forms an oligomeric ring structure and belongs to a group of DNA helicases showing extensive homology to the Escherichia coli DNA helicase RecQ, a suppressor of illegitimate recombination. After over-production in E.coli, we have purified the RecQ core of BLM consisting of the DEAH, RecQ-Ct and HRDC domains (amino acid residues 642-1290). The BLM(642-1290) fragment could function as a DNA-stimulated ATPase and as a DNA helicase, displaying the same substrate specificity as the full-size protein. Gel-filtration experiments revealed that BLM(642-1290) exists as a monomer both in solution and in its single-stranded DNA-bound form, even in the presence of Mg(2+) and ATPgammaS. Rates of ATP hydrolysis and DNA unwinding by BLM(642-1290) showed a hyperbolic dependence on ATP concentration, excluding a co-operative interaction between ATP-binding sites. Using a lambda Spi(-) assay, we have found that the BLM(642-1290) fragment is able to partially substitute for the RecQ helicase in suppressing illegitimate recombination in E.coli. A deletion of 182 C-terminal amino acid residues of BLM(642-1290), including the HRDC domain, resulted in helicase and single-stranded DNA-binding defects, whereas kinetic parameters for ATP hydrolysis of this mutant were close to the BLM(642-1290) values. This confirms the prediction that the HRDC domain serves as an auxiliary DNA-binding domain. Mutations at several conserved residues within the RecQ-Ct domain of BLM reduced ATPase and helicase activities severely as well as single-stranded DNA-binding of the enzyme. Together, these data define a minimal helicase domain of BLM and demonstrate its ability to act as a suppressor of illegitimate recombination.
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PMID:Characterization and mutational analysis of the RecQ core of the bloom syndrome protein. 1281

High risk types of human papillomavirus, such as type 18 (HPV-18), cause cervical carcinoma, one of the most frequent causes of cancer death in women worldwide. DNA replication is one of the central processes in viral maintenance, and the machinery involved is an excellent target for the design of antiviral therapy. The papillomaviral DNA replication initiation protein E1 has origin recognition and ATP-dependent DNA melting and helicase activities, and it consists of a DNA-binding domain and an ATPase/helicase domain. While monomeric in solution, E1 binds DNA as a dimer. Dimerization occurs via an interaction of hydrophobic residues on a single alpha-helix of each monomer. Here we present the crystal structure of the monomeric HPV-18 E1 DNA-binding domain refined to 1.8-A resolution. The structure reveals that the dimerization helix is significantly different from that of bovine papillomavirus type 1 (BPV-1). However, we demonstrate that the analogous residues required for E1 dimerization in BPV-1 and the low risk HPV-11 are also required for HPV-18 E1. We also present evidence that the HPV-18 E1 DNA-binding domain does not share the same nucleotide and amino acid requirements for specific DNA recognition as BPV-1 and HPV-11 E1.
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PMID:The DNA-binding domain of human papillomavirus type 18 E1. Crystal structure, dimerization, and DNA binding. 1459 6

Ki-1/57, the 57-kDa human protein antigen recognized by the CD30 antibody Ki-1, is a cytoplasmic and nuclear protein that is phosphorylated on serine and threonine residues. When isolated from the Hodgkin's lymphoma analogous cell line L540 Ki-1/57 co-immunoprecipitated with a Thr/Ser protein kinase activity. It has been also found to interact with hyaluronic acid and has therefore been termed intracellular IHABP4 (hyaluronan-binding protein 4). Recent studies demonstrated, however, that Ki-1/57 engages in specific interaction with the chromo-helicase-DNA-binding domain protein 3, a nuclear protein involved in chromatin remodeling and transcription regulation. We used the yeast two-hybrid system to find proteins interacting with Ki-1/57 and identified the adaptor protein RACK1 (receptor of activated kinase 1). Next, we confirmed this interaction in vitro and in vivo, performed detailed mapping studies of the interaction sites of Ki-1/57 and RACK-1, and demonstrated that Ki-1/57 also co-precipitates with protein kinase C (PKC) when isolated from phorbol 12-myristate 13-acetate (PMA)-activated L540 tumor cells and is a substrate for PKC phosphorylation in vitro and in vivo. Interestingly, the interaction of Ki-1/57 with RACK1 is abolished upon activation of L540 cells with PMA, which results in the phosphorylation of Ki-1/57 and its exit from the nucleus. Taken together, our data suggest that Ki-1/57 forms a stable complex with RACK-1 in unstimulated cells and upon PMA stimulation gets phosphorylated on threonine residues located at its extreme C terminus. These events associate Ki-1/57 with the RACK1/PKC pathway and may be important for the regulation of its cellular functions.
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PMID:Ki-1/57 interacts with RACK1 and is a substrate for the phosphorylation by phorbol 12-myristate 13-acetate-activated protein kinase C. 1469 38

The present study describes a newly identified protein named CReMM (chromatin-related mesenchymal modulator). The protein was studied by bioinformatic means and classified as a member of the third subfamily of chromodomain helicase DNA-binding proteins (CHD). In silico translation defined CReMM as a multiple domains protein including two chromodomains, SNF2/ATPase, helicase C domain and an A/T-DNA-binding domain (DBD). Predicted extensive post-translation phosphorylation on serine and tyrosine residues was demonstrated by Western blot in the presence and in the absence of phosphatase inhibitors using specific antibodies. Immunoprecipitated CReMM disclosed a DNA-dependent ATPase activity quantified by colorimetric assay. Electrophoresis mobility-shift assay (EMSA) validated that CReMM binds to A/T-rich DNA. CReMM is expressed in mesenchymal progenitors, as shown in vitro and in vivo. CReMM protein structural motifs and proven biochemical activities highlight its role in chromatin remodeling. Further delineation of the function of this protein will provide information about its dynamics in transcriptional regulation of mesenchymal cells.
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PMID:Characterization and functional analysis of CReMM, a novel chromodomain helicase DNA-binding protein. 1609 17

In eukaryotes, the GINS complex is essential for DNA replication and has been implicated as having a role at the replication fork. This complex consists of four paralogous GINS subunits, Psf1, Psf2, Psf3 and Sld5. Here, we identify an archaeal GINS homologue as a direct interaction partner of the MCM helicase. The core archaeal GINS complex contains two subunits that are poorly conserved homologues of the eukaryotic GINS subunits, in complex with a protein containing a domain homologous to the DNA-binding domain of bacterial RecJ. Interaction studies show that archaeal GINS interacts directly with the heterodimeric core primase. Our data suggest that GINS is important in coordinating the architecture of the replication fork and provide a mechanism to couple progression of the MCM helicase on the leading strand with priming events on the lagging strand.
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PMID:GINS, a central nexus in the archaeal DNA replication fork. 1648 22

The human protein CGI-55 has been described as a chromo-helicase-DNA-binding domain protein (CHD)-3 interacting protein and was also found to interact with the 3'-region of the plasminogen activator inhibitor (PAI)-1 mRNA. Here, we used CGI-55 as a "bait" in a yeast two-hybrid screen and identified eight interacting proteins: Daxx, Topoisomerase I binding RS (Topors), HPC2, UBA2, TDG, and protein inhibitor of activated STAT (signal transducer and activator of transcription) (PIAS)-1, -3, and -y. These proteins are either structurally or functionally associated with promyelocytic leukemia nuclear bodies (PML-NBs), protein sumoylation, or the regulation of transcription. The interactions of CGI-55 with Daxx, Topors, PIASy, and UBA2 were confirmed by in vivo colocalization experiments in HeLa cells, by using green (GFP) and red fluorescence fusion proteins. A mapping study of the CGI-55 binding site for these proteins revealed three distinct patterns of interaction. The fact that CGI-55-GFP has been localized in cytoplasm and nucleus in a dotted manner, and its interaction with proteins associated with PML-NBs, suggested that CGI-55 might be associated with nuclear bodies. Although Daxx and Topors co-localized with promyelocytic leukemia protein (PML), CGI-55 itself as well as PIASy and UBA2 showed only little co-localization with PML. However, we observed that CGI-55 localizes to the nucleolus and co-localizes with p80-coilin positive nuclear-coiled bodies.
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PMID:CGI-55 interacts with nuclear proteins and co-localizes to p80-coilin positive-coiled bodies in the nucleus. 1667 34

The chromodomain helicase DNA-binding domain (Chd) proteins belong to the SNF2-like family of ATPases that function in chromatin remodeling and assembly. These proteins are characterized by the presence of tandem chromodomains and are further subdivided based on the presence or absence of additional structural motifs. The Chd1-Chd2 subfamily is distinguished by the presence of a DNA-binding domain that recognizes AT-rich sequence. Currently, there are no reports addressing the function of the Chd2 family member. Embryonic stem cells containing a retroviral gene-trap inserted at the Chd2 locus were utilized to generate mice expressing a Chd2 protein lacking the DNA-binding domain. This mutation in Chd2 resulted in a general growth delay in homozygous mutants late in embryogenesis and in perinatal lethality. Animals heterozygous for the mutation showed decreased neonatal viability and increased susceptibility to non-neoplastic lesions affecting most primary organs. In particular, approximately 85% of the heterozygotes showed gross kidney abnormalities. Our results demonstrate that mutation of Chd2 dramatically affects mammalian development and long-term survival.
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PMID:Mutation of the SNF2 family member Chd2 affects mouse development and survival. 1681 Jun 78

The human 57 kDa Ki-1 antigen (Ki-1/57) is a cytoplasmic and nuclear protein, associated with Ser/Thr protein kinase activity, and phosphorylated at the serine and threonine residues upon cellular activation. We have shown that Ki-1/57 interacts with chromo-helicase DNA-binding domain protein 3 and with the adaptor/signaling protein receptor of activated kinase 1 in the nucleus. Among the identified proteins that interacted with Ki-1/57 in a yeast two-hybrid system was the protein arginine-methyltransferase-1 (PRMT1). Most interestingly, when PRMT1 was used as bait in a yeast two-hybrid system we were able to identify Ki-1/57 as prey among 14 other interacting proteins, the majority of which are involved in RNA metabolism or in the regulation of transcription. We found that Ki-1/57 and its putative paralog CGI-55 have two conserved Gly/Arg-rich motif clusters (RGG/RXR box, where X is any amino acid) that may be substrates for arginine-methylation by PRMT1. We observed that all Ki-1/57 protein fragments containing RGG/RXR box clusters interact with PRMT1 and are targets for methylation in vitro. Furthermore, we found that Ki-1/57 is a target for methylation in vivo. Using immunofluorescence experiments we observed that treatment of HeLa cells with an inhibitor of methylation, adenosine-2',3'-dialdehyde (Adox), led to a reduction in the cytoplasmic immunostaining of Ki-1/57, whereas its paralog CGI-55 was partially redistributed from the nucleus to the cytoplasm upon Adox treatment. In summary, our data show that the yeast two-hybrid assay is an effective system for identifying novel PRMT arginine-methylation substrates and may be successfully applied to other members of the growing family of PRMTs.
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PMID:Ki-1/57 interacts with PRMT1 and is a substrate for arginine methylation. 1687 14


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