6G7N

Trichodesmium Tery_3377 (IdiA) (FutA) with iron and alanine ligand.

6G7N の概要

• エントリーDOI: 10.2210/pdb6g7n/pdb
• 分子名称: Extracellular solute-binding protein, family 1, D-ALANINE, D-GLUTAMIC ACID, ... (5 entities in total)
• 機能のキーワード: iron, idia, futa, abc-transporter, metal binding protein
• 由来する生物種: Trichodesmium erythraeum IMS101
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70343.16

構造登録者

Machelett, M.M.,Tews, I. (登録日: 2018-04-06, 公開日: 2018-09-12, 最終更新日: 2024-05-08)

主引用文献

Polyviou, D.,Machelett, M.M.,Hitchcock, A.,Baylay, A.J.,MacMillan, F.,Moore, C.M.,Bibby, T.S.,Tews, I.
Structural and functional characterization of IdiA/FutA (Tery_3377), an iron-binding protein from the ocean diazotrophTrichodesmium erythraeum.
J. Biol. Chem., 293:18099-18109, 2018

PubMed Abstract: Atmospheric nitrogen fixation by photosynthetic cyanobacteria (diazotrophs) strongly influences oceanic primary production and in turn affects global biogeochemical cycles. Species of the genus are major contributors to marine diazotrophy, accounting for a significant proportion of the fixed nitrogen in tropical and subtropical oceans. However, spp. are metabolically constrained by the availability of iron, an essential element for both the photosynthetic apparatus and the nitrogenase enzyme. Survival strategies in low-iron environments are typically poorly characterized at the molecular level, because these bacteria are recalcitrant to genetic manipulation. Here, we studied a homolog of the iron deficiency-induced A (IdiA)/ferric uptake transporter A (FutA) protein, Tery_3377, which has been used as an iron-stress biomarker. IdiA/FutA has an ambiguous function in cyanobacteria, with its homologs hypothesized to be involved in distinct processes depending on their cellular localization. Using signal sequence fusions to GFP and heterologous expression in the model cyanobacterium sp. PCC 6803, we show that Tery_3377 is targeted to the periplasm by the twin-arginine translocase and can complement the deletion of the native ferric-iron ABC transporter periplasmic binding protein (FutA2). EPR spectroscopy revealed that purified recombinant Tery_3377 has specificity for iron in the Fe state, and an X-ray crystallography-determined structure uncovered a functional iron substrate-binding domain, with Fe pentacoordinated by protein and buffer ligands. Our results support assignment of Tery_3377 as a functional FutA subunit of an Fe ABC transporter but do not rule out dual IdiA function.

PubMed: 30217820
DOI: 10.1074/jbc.RA118.001929

実験手法

X-RAY DIFFRACTION (1.1 Å)