Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutant cell line (IF2) derived from the mouse myeloma MOPC 21 has been used for the isolation and sequence analysis of H-chain mRNA. The IF2 cells synthesise an H-chain of reduced size in which the CH1 homology region is missing. Sizing of the IF2 H-chain mRNA and wild-type H-chain mRNA revealed that the deletion is expressed at the mRNA level. The mutant H-chain mRNA sedimented at 16-S, enabling effective resolution from 18-S ribosomal RNA. In experiments using IF2 cells labelled with [32P]phosphate, the 16-S mRNA was purified by oligo(T)-cellulose chromatography. Polyacrylamide gel analysis of the poly(A)-containing fraction showed the presence of a single radioactive band. Comparison of the mobility of this band relative to markers of known molecular weight revealed that the molecule contained about 1600 nucleotides. Digestion of the 32-P-labelled mRNA with T1 ribonuclease and two-dimensional fractionation of the resulting oligonucleotides yielded a 'finger-print' suitable for a preliminary sequence analysis. By using the established amino acid sequence of the IF2 H-chain and a knowledge of the genetic code, 14 oligonucleotides were assigned within the constant region and four within the variable region of the IF2 H-chain. This sequence data accounts for 19.5% of the coding region. Several other oligonucleotides, which could not be assigned within the coding region but which occurred in approximately molar yield, have also been partially characterised. These oligonucleotides are presumably derived from the untranslated regions of mRNA.
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PMID:Purification and sequence analysis of the mRNA coding for an immunoglobulin heavy chain. 81 96

We report the crystal structure of PYCH_01220, a hypothetical protein in Pyrococcus yayanosii CH1. This protein is composed of two domains, named Domain A and Domain B. While Domain B is not significantly homologous to known protein structures, Domain A is structurally analogous to the C-terminal ribonuclease domain of Escherichia coli colicin D. Domain A has a positively charged surface patch rendered by 13 basic residues, eight arginine or lysine residues of which are evolutionarily conserved. Electrophoretic mobility shift assays showed that PYCH_01220 binds to DNA, and charge-inversion mutations on this patch negatively affect the DNA binding, suggesting that the function of PYCH_01220 might involve nucleic acid-binding via the positively charged patch. This article is protected by copyright. All rights reserved.
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PMID:Crystal structure of PYCH_01220 from Pyrococcus yayanosii potentially involved in binding nucleic acid. 3323 9