7KWH

Spermidine N-acetyltransferase SpeG K23-Y30 chimera from Vibrio cholerae and hSSAT

7KWH の概要

• エントリーDOI: 10.2210/pdb7kwh/pdb
• 分子名称: Spermidine N(1)-acetyltransferase, PHOSPHATE ION (2 entities in total)
• 機能のキーワード: speg enzyme allosteric, transferase
• 由来する生物種: Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 249933.32

構造登録者

Le, V.T.B.,Tsimbalyuk, S.,Lim, E.Q.,Solis, A.,Gawat, D.,Boeck, P.,Renolo, R.,Forwood, J.K. (登録日: 2020-12-01, 公開日: 2020-12-16, 最終更新日: 2023-10-18)

主引用文献

Le, V.T.B.,Tsimbalyuk, S.,Lim, E.Q.,Solis, A.,Gawat, D.,Boeck, P.,Lim, E.Q.,Renolo, R.,Forwood, J.K.,Kuhn, M.L.
The Vibrio cholerae SpeG Spermidine/Spermine N -Acetyltransferase Allosteric Loop and beta 6-beta 7 Structural Elements Are Critical for Kinetic Activity.
Front Mol Biosci, 8:645768-645768, 2021

PubMed Abstract: Polyamines regulate many important biological processes including gene expression, intracellular signaling, and biofilm formation. Their intracellular concentrations are tightly regulated by polyamine transport systems and biosynthetic and catabolic pathways. Spermidine/spermine -acetyltransferases (SSATs) are catabolic enzymes that acetylate polyamines and are critical for maintaining intracellular polyamine homeostasis. These enzymes belong to the Gcn5-related -acetyltransferase (GNAT) superfamily and adopt a highly conserved fold found across all kingdoms of life. SpeG is an SSAT protein found in a variety of bacteria, including the human pathogen This protein adopts a dodecameric structure and contains an allosteric site, making it unique compared to other SSATs. Currently, we have a limited understanding of the critical structural components of this protein that are required for its allosteric behavior. Therefore, we explored the importance of two key regions of the SpeG protein on its kinetic activity. To achieve this, we created various constructs of the SpeG protein, including point mutations, a deletion, and chimeras with residues from the structurally distinct and non-allosteric human SSAT protein. We measured enzyme kinetic activity toward spermine for ten constructs and crystallized six of them. Ultimately, we identified specific portions of the allosteric loop and the β6-β7 structural elements that were critical for enzyme kinetic activity. These results provide a framework for further study of the structure/function relationship of SpeG enzymes from other organisms and clues toward the structural evolution of members of the GNAT family across domains of life.

PubMed: 33928120
DOI: 10.3389/fmolb.2021.645768

実験手法

X-RAY DIFFRACTION (2.9 Å)