PDBsum entry 4xgo

Protein binding

PDB id: 4xgo

Contents

Protein chains

340 a.a.

Ligands

NAG-NAG ×2

PO4 ×3

ACT ×2

GOL ×6

Metals

_CL ×2

_NA

Waters ×781

PDB id:

4xgo

Name:

Protein binding

Title:

Crystal structure of leucine-rich repeat domain of apl1b

Structure:

Anopheles plasmodium-responsive leucine-rich repeat protein 1b. Chain: a, b. Fragment: residues 21-370. Synonym: apl1b. Engineered: yes

Source:

Anopheles gambiae. African malaria mosquito. Organism_taxid: 7165. Gene: apl1b. Expressed in: trichoplusia ni. Expression_system_taxid: 7111.

Resolution:

1.74Å R-factor: 0.188 R-free: 0.220

Authors:

M.Williams,B.Summers,R.H.G.Baxter

Key ref:

M.Williams et al. (2015). Biophysical analysis of anopheles gambiae leucine-rich repeat proteins APL1A1, APL1B [corrected] and APL1C and their interaction with LRIM1. Plos One, 10, e0118911. PubMed id: 25775123 DOI: 10.1371/journal.pone.0118911

Date:

01-Jan-15 Release date: 01-Apr-15

Protein chains

F2YBL9  (F2YBL9_ANOGA) -  APL1B from Anopheles gambiae

Seq: 555 a.a.

Struc: 340 a.a.*

* PDB and UniProt seqs differ at 8 residue positions (black crosses)

DOI no: 10.1371/journal.pone.0118911

Plos One 10:e0118911 (2015)

PubMed id: 25775123

Biophysical analysis of anopheles gambiae leucine-rich repeat proteins APL1A1, APL1B [corrected] and APL1C and their interaction with LRIM1.

M.Williams, B.J.Summers, R.H.Baxter.

ABSTRACT

Natural infection of Anopheles gambiae by malaria-causing Plasmodium parasites is significantly influenced by the APL1 genetic locus. The locus contains three closely related leucine-rich repeat (LRR) genes, APL1A, APL1B and APL1C. Multiple studies have reported the participation of APL1A-C in the immune response of A. gambiae to invasion by both rodent and human Plasmodium isolates. APL1C forms a heterodimer with the related LRR protein LRIM1 via a C-terminal coiled-coil domain that is also present in APL1A and APL1B. The LRIM1/APL1C heterodimer protects A. gambiae from infection by binding the complement-like protein TEP1 to form a stable and active immune complex. Here we report solution x-ray scatting data for the LRIM1/APL1C heterodimer, the oligomeric state of LRIM1/APL1 LRR domains in solution and the crystal structure of the APL1B LRR domain. The LRIM1/APL1C heterodimeric complex has a flexible and extended structure in solution. In contrast to the APL1A, APL1C and LRIM1 LRR domains, the APL1B LRR domain is a homodimer. The crystal structure of APL1B-LRR shows that the homodimer is formed by an N-terminal helix that complements for the absence of an N-terminal capping motif in APL1B, which is a unique distinction within the LRIM1/APL1 protein family. Full-length APL1A1 and APL1B form a stable complex with LRIM1. These results support a model in which APL1A1, APL1B and APL1C can all form an extended, flexible heterodimer with LRIM1, providing a repertoire of functional innate immune complexes to protect A. gambiae from a diverse array of pathogens.