4V16

KlHsv2 with loop 6CD replaced by a Gly-Ser linker

4V16 の概要

• エントリーDOI: 10.2210/pdb4v16/pdb
• 分子名称: SVP1-LIKE PROTEIN 2 (2 entities in total)
• 機能のキーワード: protein transport, proppin, phosphoinositide binding
• 由来する生物種: KLUYVEROMYCES LACTIS
• 細胞内の位置: Vacuole membrane ; Peripheral membrane protein : Q6CN23
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37563.87

構造登録者

Busse, R.A.,Scacioc, A.,Krick, R.,Perez-Lara, A.,Thumm, M.,Kuhnel, K. (登録日: 2014-09-25, 公開日: 2015-04-01, 最終更新日: 2024-01-10)

主引用文献

Busse, R.A.,Scacioc, A.,Krick, R.,Perez-Lara, A.,Thumm, M.,Kuhnel, K.
Characterization of Proppin-Phosphoinositide Binding and Role of Loop 6Cd in Proppin-Membrane Binding.
Biophys.J., 108:2223-, 2015

PubMed Abstract: PROPPINs (β-propellers that bind polyphosphoinositides) are a family of PtdIns3P- and PtdIns(3,5)P2-binding proteins that play an important role in autophagy. We analyzed PROPPIN-membrane binding through isothermal titration calorimetry (ITC), stopped-flow measurements, mutagenesis studies, and molecular dynamics (MD) simulations. ITC measurements showed that the yeast PROPPIN family members Atg18, Atg21, and Hsv2 bind PtdIns3P and PtdIns(3,5)P2 with high affinities in the nanomolar to low-micromolar range and have two phosphoinositide (PIP)-binding sites. Single PIP-binding site mutants have a 15- to 30-fold reduced affinity, which explains the requirement of two PIP-binding sites in PROPPINs. Hsv2 bound small unilamellar vesicles with a higher affinity than it bound large unilamellar vesicles in stopped-flow measurements. Thus, we conclude that PROPPIN membrane binding is curvature dependent. MD simulations revealed that loop 6CD is an anchor for membrane binding, as it is the region of the protein that inserts most deeply into the lipid bilayer. Mutagenesis studies showed that both hydrophobic and electrostatic interactions are required for membrane insertion of loop 6CD. We propose a model for PROPPIN-membrane binding in which PROPPINs are initially targeted to membranes through nonspecific electrostatic interactions and are then retained at the membrane through PIP binding.

PubMed: 25954880
DOI: 10.1016/J.BPJ.2015.03.045

実験手法

X-RAY DIFFRACTION (2.8 Å)