EC Number   |
General Information |
Reference |
|---|
   2.1.1.309 | evolution |
Bud23 is a class I S-adenosyl-L-methionine (SAM)-dependent MTase |
720457 |
| 2.1.1.309 | evolution |
WBSCR22-TRMT112 is the functional homologue of Saccharomyces cerevisiae Bud23-Trm112 |
736779 |
| 2.1.1.309 | malfunction |
deletion of BUD23 leads to severely impaired growth, reduced levels of the small (40S) ribosomal subunit, and a block in processing 20S rRNA to 18S rRNA, a late step in 40S maturation |
713014 |
| 2.1.1.309 | malfunction |
DELTAbud23 mutants have severely reduced small subunit levels and showa general failure in cleavage at site A2 during rRNA processing. A2 cleavage in a DELTAbud23 mutant is inefficient, with a marked reduction in the levels of 27S A2 intermediate. In the absence of A2 cleavage, cleavage at A3 is likely to be essential for separating the precursors for 40S and 60S processing. The strong negative genetic interaction observed between DELTAbud23 and RNase MRP components may reflect such a block in rRNA processing. Utp14 particle in a DELTAbud23 mutant contains U3 snoRNA but lacks 20S pre-rRNA. Phenotypes, overview. Although BUD23 is not essential for viability, deletion of the gene results in a severe slow-growth phenotype |
737229 |
| 2.1.1.309 | malfunction |
HeLa cells depleted of WBSCR22 show a mild reduction in 30S, indicative of reduced cleavage at site 2, and significant accumulation of 18S-E revealing inhibition of cleavage at site 3. Long and short truncated forms of 18S precursors are detected. On WBSCR22 depletion, the amount of mature 18S rRNA is markedly reduced and the 28S/18S rRNA ratio consequently increased. TRMT112 depletion leads to processing phenotypes largely similar to those observed upon WBSCR22 depletion (moderate 30S reduction and accumulation of 18S-E). The processing defects do not depend on p53 and are essentially the same, with minor differences, in different cell types. Kinetics of the pre-rRNA processing defects in HeLa cells by in vivo metabolic labeling, phenotype, overview |
736779 |
| 2.1.1.309 | malfunction |
trm112DELTA cells are deficient for Bud23-mediated 18S rRNA methylation at position G1575 and for small ribosome subunit formation. Bud23 failure to bind nascent preribosomes activates a nucleolar surveillance pathway involving the TRAMP complexes, leading to preribosome degradation |
720457 |
| 2.1.1.309 | metabolism |
Bud23 failure to bind nascent preribosomes activates a nucleolar surveillance pathway involving the TRAMP complexes, leading to preribosome degradation |
720457 |
| 2.1.1.309 | metabolism |
DIMT1L, WBSCR22, and TRMT112 are required for distinct pre-rRNA processing steps, and the pre-rRNA processing defects are conserved in different cell types and do not depend on p53 |
736779 |
| 2.1.1.309 | more |
Bud23 and Trm112 interact through formation of a beta-zipper involving main-chain atoms, burying an important hydrophobic surface and stabilizing the complex. The structures reveal that the coactivator Trm112 undergoes an induced fit to accommodate its methyltransferase (MTase) partner, identification of Bud23 residues important for Bud23-Trm112 complex formation and recruitment to pre-ribosomes |
737170 |
| 2.1.1.309 | physiological function |
Bud23 is responsible for the conserved methylation of G1575 of 18S rRNA, in the P-site of the small subunit of the ribosome. Bud23 protein, but not its methyltransferase activity, is important for its function. Bud23 is required for efficient A2 cleavage. Bud23 is required for the proper localization of small subunit components, UTP proteins mislocalize to the nucleoplasm in the absence of Bud23 |
737229 |
