PDBsum entry 3wo9

Immune system

PDB id: 3wo9

Contents

Protein chain

223 a.a.

Waters ×101

PDB id:

3wo9

Name:

Immune system

Title:

Crystal structure of the lamprey variable lymphocyte receptor c

Structure:

Variable lymphocyte receptor c. Chain: a. Fragment: vlrc ectodomain, unp residues 25-246. Engineered: yes

Source:

Lethenteron camtschaticum. Japanese lamprey. Organism_taxid: 980415. Gene: vlrc. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.30Å R-factor: 0.184 R-free: 0.238

Authors:

R.Kanda,Y.Sutoh,J.Kasamatsu,K.Maenaka,M.Kasahara,T.Ose

Key ref:

R.Kanda et al. (2014). Crystal structure of the lamprey variable lymphocyte receptor C reveals an unusual feature in its N-terminal capping module. Plos One, 9, e85875. PubMed id: 24465760 DOI: 10.1371/journal.pone.0085875

Date:

20-Dec-13 Release date: 05-Mar-14

Protein chain

E0D2V6  (E0D2V6_LETCA) -  Variable lymphocyte receptor C from Lethenteron camtschaticum

Seq: 320 a.a.

Struc: 223 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

DOI no: 10.1371/journal.pone.0085875

Plos One 9:e85875 (2014)

PubMed id: 24465760

Crystal structure of the lamprey variable lymphocyte receptor C reveals an unusual feature in its N-terminal capping module.

R.Kanda, Y.Sutoh, J.Kasamatsu, K.Maenaka, M.Kasahara, T.Ose.

ABSTRACT

Jawless vertebrates represented by lampreys and hagfish use variable lymphocyte receptors (VLRs) as antigen receptors to mount adaptive immune responses. VLRs generate diversity that is comparable to immunoglobulins and T-cell receptors by a gene conversion-like mechanism, which is mediated by cytosine deaminases. Currently, three types of VLRs, VLRA, VLRB, and VLRC, have been identified in lampreys. Crystal structures of VLRA and VLRB in complex with antigens have been reported recently, but no structural information is available for VLRC. Here, we present the first crystal structure of VLRC from the Japanese lamprey (Lethenteron japonicum). Similar to VLRA and VLRB, VLRC forms a typical horseshoe-like solenoid structure with a variable concave surface. Strikingly, its N-terminal cap has a long loop with limited sequence variability that protrudes toward the concave surface, which is the putative antigen-binding surface. Furthermore, as predicted previously, its C-terminal cap lacks a highly variable protruding loop that plays an important role in antigen recognition by lamprey VLRA and VLRB. Recent work suggests that VLRC+ lymphocytes in jawless vertebrates might be akin to γδ T cells in jawed vertebrates. Structural features of lamprey VLRC described here suggest that it may recognize antigens in a unique manner.