1QYR

2.1 Angstrom Crystal structure of KsgA: A Universally Conserved Adenosine Dimethyltransferase

1QYR の概要

• エントリーDOI: 10.2210/pdb1qyr/pdb
• 分子名称: High level Kasugamycin resistance protein (2 entities in total)
• 機能のキーワード: kasugamycin resistance; adenosine dimethyltransferase; rrna modification, transferase, translation
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 55976.55

構造登録者

O'Farrell, H.C.,Scarsdale, J.N.,Wright, H.T.,Rife, J.P. (登録日: 2003-09-11, 公開日: 2004-06-29, 最終更新日: 2024-02-14)

主引用文献

O'Farrell, H.C.,Scarsdale, J.N.,Rife, J.P.
Crystal structure of KsgA, a universally conserved rRNA adenine dimethyltransferase in Escherichia coli
J.Mol.Biol., 339:337-353, 2004

PubMed Abstract: The bacterial enzyme KsgA catalyzes the transfer of a total of four methyl groups from S-adenosyl-l-methionine (S-AdoMet) to two adjacent adenosine bases in 16S rRNA. This enzyme and the resulting modified adenosine bases appear to be conserved in all species of eubacteria, eukaryotes, and archaebacteria, and in eukaryotic organelles. Bacterial resistance to the aminoglycoside antibiotic kasugamycin involves inactivation of KsgA and resulting loss of the dimethylations, with modest consequences to the overall fitness of the organism. In contrast, the yeast ortholog, Dim1, is essential. In yeast, and presumably in other eukaryotes, the enzyme performs a vital role in pre-rRNA processing in addition to its methylating activity. Another ortholog has been discovered recently, h-mtTFB in human mitochondria, which has a second function; this enzyme is a nuclear-encoded mitochondrial transcription factor. The KsgA enzymes are homologous to another family of RNA methyltransferases, the Erm enzymes, which methylate a single adenosine base in 23S rRNA and confer resistance to the MLS-B group of antibiotics. Despite their sequence similarity, the two enzyme families have strikingly different levels of regulation that remain to be elucidated. We have crystallized KsgA from Escherichia coli and solved its structure to a resolution of 2.1A. The structure bears a strong similarity to the crystal structure of ErmC' from Bacillus stearothermophilus and a lesser similarity to sc-mtTFB, the Saccharomyces cerevisiae version of h-mtTFB. Comparison of the three crystal structures and further study of the KsgA protein will provide insight into this interesting group of enzymes.

PubMed: 15136037
DOI: 10.1016/j.jmb.2004.02.068

実験手法

X-RAY DIFFRACTION (2.1 Å)