2LLA image
Entry Detail
PDB ID:
2LLA
Title:
NMR solution structure ensemble of domain 11 of the echidna M6P/IGF2R receptor
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2011-11-05
Release Date:
2012-11-07
Method Details:
Experimental Method:
Conformers Calculated:
100
Conformers Submitted:
20
Selection Criteria:
STRUCTURES WITH THE LOWEST ENER
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Mannose-6-phosphate/insulin-like growth factor II receptor
Chain IDs:A
Chain Length:140
Number of Molecules:1
Biological Source:Tachyglossus aculeatus
Ligand Molecules
Primary Citation
An exon splice enhancer primes IGF2:IGF2R binding site structure and function evolution.
Science 338 1209 1213 (2012)
PMID: 23197533 DOI: 10.1126/science.1228633

Abstact

Placental development and genomic imprinting coevolved with parental conflict over resource distribution to mammalian offspring. The imprinted genes IGF2 and IGF2R code for the growth promoter insulin-like growth factor 2 (IGF2) and its inhibitor, mannose 6-phosphate (M6P)/IGF2 receptor (IGF2R), respectively. M6P/IGF2R of birds and fish do not recognize IGF2. In monotremes, which lack imprinting, IGF2 specifically bound M6P/IGF2R via a hydrophobic CD loop. We show that the DNA coding the CD loop in monotremes functions as an exon splice enhancer (ESE) and that structural evolution of binding site loops (AB, HI, FG) improved therian IGF2 affinity. We propose that ESE evolution led to the fortuitous acquisition of IGF2 binding by M6P/IGF2R that drew IGF2R into parental conflict; subsequent imprinting may then have accelerated affinity maturation.

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Primary Citation of related structures