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)

The mammalian ribosomal protein S3 (rpS3) is a component of the 40S ribosomal subunit. It is known to function as a DNA repair enzyme, UV endonuclease III, which cleaves DNA that is irradiated by UV. It also has an endonuclease activity on AP DNA. In this report, the yeast ribosomal protein S3 (Rps3p) in S. cerevisiae was cloned, expressed in E. coli, and affinity-purified by 285 fold. Rps3p is composed of 240 amino acids and has a 78% amino acid similarity with the human counterpart that has 243 amino acids. The major difference in the amino acid sequence between the two proteins lies in most of the C-terminal 50 residues. Surprisingly, Rps3p only showed an endonuclease activity on AP DNA, but not on DNA that was irradiated with UV. The AP endonuclease activity of Rps3p was affected by pH, KCl, and beta-mercaptoethanol, but Triton X-100 and EDTA did not affect the enzyme activity. From these results, both the mammalian rpS3 and Rps3p appear to be involved in DNA damage processing, but in different modes.
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PMID:Yeast ribosomal protein S3 has an endonuclease activity on AP DNA. 1156 34

Ribosomal protein S3 (RPS3) is a multifunctional ribosomal protein: it is a structural and functional component of the ribosome, and also a DNA repair enzyme involved in the DNA base excision repair pathway. Here we cloned and characterized the genomic organization of the ribosomal protein S3 gene (RpS3) homolog in Drosophila virilis. We then compared gene structure and protein sequences of RpS3 from vertebrates, invertebrates, and plants. These comparisons revealed that RpS3 genes from plants to mammals have highly conserved coding and amino acid sequences, and also protein size. Further comparisons of the protein sequences show that important domains are well conserved in both localization and sequence. In contrast, comparison of gene size and organization reveals differing patterns and levels of conservation. Whereas invertebrate RpS3 genes are small in size and gene organization is variable (from zero to four introns), vertebrates have a considerably larger (but variable) gene size and a uniform gene organization. The larger gene size in vertebrates is due to increased number and expansion of introns. Although the plant RpS3 genes are relatively small ( approximately 1.8 kb), their organization resembles that seen in vertebrates. The high conservation through different phyla may suggest that RPS3 might be under great functional constraints, both in its capacity as a component of the ribosome and as a component of a DNA repair system. Finally, electrophoretic mobility shift assays indicate that an upstream element binds a nuclear protein(s).
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PMID:Organization, sequence, and phylogenetic analysis of the ribosomal protein S3 gene from Drosophila virilis. 1223 76