7A0H

Structure of homodimeric actin capping protein alpha subunit from Plasmodium berghei

7A0H の概要

• エントリーDOI: 10.2210/pdb7a0h/pdb
• 分子名称: F-actin-capping protein subunit alpha, BROMIDE ION, GLYCEROL, ... (5 entities in total)
• 機能のキーワード: capping protein, f-actin binding, asymmetric homodimer, protein binding
• 由来する生物種: Plasmodium berghei (strain Anka)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70593.76

構造登録者

Bendes, A.A.,Kursula, P.,Kursula, I. (登録日: 2020-08-09, 公開日: 2021-08-18, 最終更新日: 2022-02-23)

主引用文献

Bendes, A.A.,Kursula, P.,Kursula, I.
Structure and function of an atypical homodimeric actin capping protein from the malaria parasite.
Cell.Mol.Life Sci., 79:125-125, 2022

PubMed Abstract: Apicomplexan parasites, such as Plasmodium spp., rely on an unusual actomyosin motor, termed glideosome, for motility and host cell invasion. The actin filaments are maintained by a small set of essential regulators, which provide control over actin dynamics in the different stages of the parasite life cycle. Actin filament capping proteins (CPs) are indispensable heterodimeric regulators of actin dynamics. CPs have been extensively characterized in higher eukaryotes, but their role and functional mechanism in Apicomplexa remain enigmatic. Here, we present the first crystal structure of a homodimeric CP from the malaria parasite and compare the homo- and heterodimeric CP structures in detail. Despite retaining several characteristics of a canonical CP, the homodimeric Plasmodium berghei (Pb)CP exhibits crucial differences to the canonical heterodimers. Both homo- and heterodimeric PbCPs regulate actin dynamics in an atypical manner, facilitating rapid turnover of parasite actin, without affecting its critical concentration. Homo- and heterodimeric PbCPs show partially redundant activities, possibly to rescue actin filament capping in life cycle stages where the β-subunit is downregulated. Our data suggest that the homodimeric PbCP also influences actin kinetics by recruiting lateral actin dimers. This unusual function could arise from the absence of a β-subunit, as the asymmetric PbCP homodimer lacks structural elements essential for canonical barbed end interactions suggesting a novel CP binding mode. These findings will facilitate further studies aimed at elucidating the precise actin filament capping mechanism in Plasmodium.

PubMed: 35132495
DOI: 10.1007/s00018-021-04032-0

実験手法

X-RAY DIFFRACTION (2.22 Å)