PDBsum entry 1j2h

Protein transport

PDB id: 1j2h

Contents

Protein chain

112 a.a.

Waters ×111

Superseded by:

1o3x

PDB id:

1j2h

Name:

Protein transport

Title:

Crystal structure of human gga1 gat domain

Structure:

Adp-ribosylation factor binding protein gga1. Chain: a. Fragment: gat domain. Engineered: yes

Source:

Homo sapiens. Human. Expressed in: escherichia coli.

Resolution:

2.10Å R-factor: 0.247 R-free: 0.290

Authors:

T.Shiba,M.Kawasaki,H.Takatsu,T.Nogi,N.Matsugaki,N.Igarashi, M.Suzuki,R.Kato,K.Nakayama,S.Wakatsuki

Key ref:

T.Shiba et al. (2003). Molecular mechanism of membrane recruitment of GGA by ARF in lysosomal protein transport. Nat Struct Biol, 10, 386-393. PubMed id: 12679809 DOI: 10.1038/nsb920

Date:

05-Jan-03 Release date: 06-May-03

Protein chain

Q9UJY5  (GGA1_HUMAN) -  ADP-ribosylation factor-binding protein GGA1 from Homo sapiens

Seq: 639 a.a.

Struc: 112 a.a.

DOI no: 10.1038/nsb920

Nat Struct Biol 10:386-393 (2003)

PubMed id: 12679809

Molecular mechanism of membrane recruitment of GGA by ARF in lysosomal protein transport.

T.Shiba, M.Kawasaki, H.Takatsu, T.Nogi, N.Matsugaki, N.Igarashi, M.Suzuki, R.Kato, K.Nakayama, S.Wakatsuki.

ABSTRACT

GGAs are critical for trafficking soluble proteins from the trans-Golgi network (TGN) to endosomes/lysosomes through interactions with TGN-sorting receptors, ADP-ribosylation factor (ARF) and clathrin. ARF-GTP bound to TGN membranes recruits its effector GGA by binding to the GAT domain, thus facilitating recognition of GGA for cargo-loaded receptors. Here we report the X-ray crystal structures of the human GGA1-GAT domain and the complex between ARF1-GTP and the N-terminal region of the GAT domain. When unbound, the GAT domain forms an elongated bundle of three a-helices with a hydrophobic core. Structurally, this domain, combined with the preceding VHS domain, resembles CALM, an AP180 homolog involved in endocytosis. In the complex with ARF1-GTP, a helix-loop-helix of the N-terminal part of GGA1-GAT interacts with the switches 1 and 2 of ARF1 predominantly in a hydrophobic manner. These data reveal a molecular mechanism underlying membrane recruitment of adaptor proteins by ARF-GTP.

Selected figure(s)

Figure 1.
Figure 1. Structures of the GGA1-GAT domain and its complex with ARF1. a, Stereo diagram of the GGA1-GAT domain. The GAT domain forms three -helices connected by loops of varying length. The final model is complete except for the N-terminal 26 residues (166 -191, dotted line) and the C-terminal 2 residues (304 -305), whose electron density is weak. b, Stereo view of the omit F[o] -F[c] electron density map of the GGA1 N-GAT (Leu178 -Asn194) within the ARF1 -N-GAT complex. The map was calculated to 1.6 Å resolution and is displayed at 1.5 cutoff, superimposed with a ball-and-stick model of the N-GAT domain. c, Stereo view of the ARF1 -N-GAT complex. N-GAT forms a helix-loop-helix motif facing switches 1 and 2 of ARF1-GTP. The diagrams in (a) and (c) are shown in the same orientation, which was chosen by the least-square minimization of the overlap of a common helical region (199 -205, shown in red in a and c) between the GAT domain and the ARF1 -N-GAT complex.

Figure 6.
Figure 6. Domain organization of GGA and a proposed model of the interactions with its partners at several stages of the vesicle formation: M6PR, ARF -GTP, clathrin N-terminal propeller and an accessory protein. The N-terminal VHS domain recognizes the sorting signals, such as M6PR (PDB entry 1JWG). The GAT domain interacts with a membrane-bound ARF (this study). The subsequent hinge region interacts with clathrin (clathrin terminal domain in complex with the clathrin-box peptide from 3-hinge of AP-3; PDB entry 1C9I). The sequence S*LLDDELM interact with VHS domain (autoinhibition), where S* is phosphorylated^24. Finally, the C-terminal GGA1 GAE domain is modeled from the structure of the ear domain of -adaptin (PDB entry 1IU1) based on their similarity both in sequence and function.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Biol (2003, 10, 386-393) copyright 2003.

Figures were selected by an automated process.