7JP2

Crystal structure of TP0037 from Treponema pallidum, a D-lactate dehydrogenase

7JP2 の概要

• エントリーDOI: 10.2210/pdb7jp2/pdb
• 分子名称: D-lactate dehydrogenase, 1,2-ETHANEDIOL, CHLORIDE ION, ... (4 entities in total)
• 機能のキーワード: d-lactate dehydrogenase, spirochete, acetogenesis, oxidoreductase
• 由来する生物種: Treponema pallidum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 75088.80

構造登録者

Brautigam, C.A.,Deka, R.K.,Norgard, M.V. (登録日: 2020-08-07, 公開日: 2020-09-09, 最終更新日: 2023-10-18)

主引用文献

Deka, R.K.,Liu, W.Z.,Norgard, M.V.,Brautigam, C.A.
Biophysical and Biochemical Characterization of TP0037, a d-Lactate Dehydrogenase, Supports an Acetogenic Energy Conservation Pathway in Treponema pallidum.
Mbio, 11:-, 2020

PubMed Abstract: A longstanding conundrum in biology concerns how the spirochete generates sufficient energy to fulfill its complex pathogenesis processes during human syphilitic infection. For decades, it has been assumed that the bacterium relies solely on glucose catabolism (via glycolysis) for generation of its ATP. However, the organism's robust motility, believed to be essential for human tissue invasion and dissemination, would require abundant ATP likely not provided by the parsimony of glycolysis. As such, additional ATP generation, either via a chemiosmotic gradient, substrate-level phosphorylation, or both, likely exists in Along these lines, we have hypothesized that exploits an acetogenic energy conservation pathway that relies on the redox chemistry of flavins. Central to this hypothesis is the apparent existence in of an acetogenic pathway for the conversion of d-lactate to acetate. Herein we have characterized the structural, biophysical, and biochemical properties of the first enzyme (d-lactate dehydrogenase [d-LDH]; TP0037) predicted in this pathway. Binding and enzymatic studies showed that recombinant TP0037 consumed d-lactate and NAD to produce pyruvate and NADH. The crystal structure of TP0037 revealed a fold similar to that of other d-acid dehydrogenases; residues in the cofactor-binding and active sites were homologous to those of other known d-LDHs. The crystal structure and solution biophysical experiments revealed the protein's propensity to dimerize, akin to other d-LDHs. This study is the first to elucidate the enzymatic properties of 's d-LDH, thereby providing new compelling evidence for a flavin-dependent acetogenic energy conservation (ATP-generating) pathway in Because lacks a Krebs cycle and the capability for oxidative phosphorylation, historically it has been difficult to reconcile how the syphilis spirochete generates sufficient ATP to fulfill its energy needs, particularly for its robust motility, solely from glycolysis. We have postulated the existence in of a flavin-dependent acetogenic energy conservation pathway that would generate additional ATP for bioenergetics. In the proposed acetogenic pathway, first d-lactate would be converted to pyruvate. Pyruvate would then be metabolized to acetate in three additional steps, with ATP being generated via substrate-level phosphorylation. This study provides structural, biochemical, and biophysical evidence for the first enzyme in the pathway (TP0037; d-lactate dehydrogenase) requisite for the conversion of d-lactate to pyruvate. The findings represent the first experimental evidence to support a role for an acetogenic energy conservation pathway that would contribute to nonglycolytic ATP production in .

PubMed: 32963009
DOI: 10.1128/mBio.02249-20

実験手法

X-RAY DIFFRACTION (1.38 Å)