6OZW

Crystal structure of the 65-kilodalton amino-terminal fragment of DNA topoisomerase I from Streptococcus mutans

6OZW の概要

• エントリーDOI: 10.2210/pdb6ozw/pdb
• 分子名称: DNA topoisomerase 1, MAGNESIUM ION, FORMIC ACID, ... (4 entities in total)
• 機能のキーワード: topoisomerase, supercoiled, dna binding protein, isomerase
• 由来する生物種: Streptococcus mutans serotype c (strain ATCC 700610 / UA159)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 68573.57

構造登録者

Jones, J.A.,Hevener, K.E. (登録日: 2019-05-16, 公開日: 2019-06-26, 最終更新日: 2023-10-11)

主引用文献

Jones, J.A.,Hevener, K.E.
Crystal structure of the 65-kilodalton amino-terminal fragment of DNA topoisomerase I from the gram-positive model organism Streptococcus mutans.
Biochem.Biophys.Res.Commun., 516:333-338, 2019

PubMed Abstract: Herein we report the first structure of topoisomerase I determined from the gram-positive bacterium, S. mutans. Bacterial topoisomerase I is an ATP-independent type 1A topoisomerase that uses the inherent torsional strain within hyper-negatively supercoiled DNA as an energy source for its critical function of DNA relaxation. Interest in the enzyme has gained momentum as it has proven to be essential in various bacterial organisms. In order to aid in further biochemical characterization, the apo 65-kDa amino-terminal fragment of DNA topoisomerase I from the gram-positive model organism Streptococcus mutans was crystalized and a three-dimensional structure was determined to 2.06 Å resolution via x-ray crystallography. The overall structure illustrates the four classic major domains that create the traditional topoisomerase I "lock" formation comprised of a sizable toroidal aperture atop what is considered to be a highly dynamic body. A catalytic tyrosine residue resides at the interface between two domains and is known to form a 5' phosphotyrosine DNA-enzyme intermediate during transient single-stranded cleavage required for enzymatic relaxation of hyper negative DNA supercoils. Surrounding the catalytic tyrosine residue is the remainder of the highly conserved active site. Within 5 Å from the catalytic center, only one dissimilar residue is observed between topoisomerase I from S. mutans and the gram-negative model organism E. coli. Immediately adjacent to the conserved active site, however, S. mutans topoisomerase I displays a somewhat unique nine residue loop extension not present in any bacterial topoisomerase I structures previously determined other than that of an extremophile.

PubMed: 31204053
DOI: 10.1016/j.bbrc.2019.06.034

実験手法

X-RAY DIFFRACTION (2.063 Å)