Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.5.1.2 (DNA ligase)
 2,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Upstream binding factor (UBF) is an important transactivator of RNA polymerase I and is a member of a family of proteins that contain nucleic acid binding domains named high-mobility-group (HMG) boxes because of their similarity to HMG chromosomal proteins. UBF is a highly sequence-tolerant DNA-binding protein for which no binding consensus sequence has been identified. Therefore, it has been suggested that UBF may recognize preformed structural features of DNA, a hypothesis supported by UBF's ability to bind synthetic DNA cruciforms, four-way junctions, and even tRNA. We show here that full-length UBF can also bend linear DNA to mediate circularization of probes as small as 102 bp in the presence of DNA ligase. Longer probes in the presence of UBF become positively supercoiled when ligated, suggesting that UBF wraps the DNA in a right-handed direction, opposite the direction of DNA wrapping around a nucleosome. The dimerization domain and HMG box 1 are necessary and sufficient to circularize short probes and supercoil longer probes in the presence of DNA ligase. UBF's sequence tolerance coupled with its ability to bend and wrap DNA makes UBF an unusual eukaryotic transcription factor. However, UBF's ability to bend DNA might explain how upstream and downstream rRNA gene promoter domains interact. UBF-induced DNA wrapping could also be a mechanism by which UBF counteracts histone-mediated gene repression.
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PMID:The RNA polymerase I transactivator upstream binding factor requires its dimerization domain and high-mobility-group (HMG) box 1 to bend, wrap, and positively supercoil enhancer DNA. 793 71

The phylogeny of 13 viral species in the genera Granulovirus and Nucleopolyhedrovirus (family Baculoviridae) was reconstructed on the basis of 22 conserved protein families shared by all species, and a comprehensive homology search and phylogenetic analysis of the complete genomes of these viruses was used to test for horizontal gene transfer from cellular organisms. Statistically significant evidence of horizontal transfer was found in the case of six protein families (DNA ligase, ribonucleotide reductase 1, SNF2 global transactivator, inhibitor of apoptosis, chitinase, and UDP-glucosyltransferase). Three of these families are known to play key roles in the infection of insect hosts by these viruses. There was evidence that two of these (inhibitor of apoptosis and UDP-glucosyltransferase) were derived from the insect host. By contrast, the gene encoding chitinase in these viruses was evidently derived from a group of bacteria (the gamma subdivision of proteobacteria), which use chitinase to break down fungal chitins.
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PMID:Genome-wide survey for genes horizontally transferred from cellular organisms to baculoviruses. 1271 88