Structural Basis for Rare Earth Element Recognition by Methylobacterium extorquens Lanmodulin

Lanmodulin (LanM) is a high-affinity lanthanide (Ln)-binding protein recently identified in Methylobacterium extorquens, a bacterium that requires Lns for the function of at least two enzymes. LanM possesses four EF-hands, metal coordination motifs generally associated with CaII binding, but it unde...

Full description

Saved in:
Bibliographic Details
Published inBiochemistry (Easton) Vol. 58; no. 2; pp. 120 - 125
Main Authors Cook, Erik C, Featherston, Emily R, Showalter, Scott A, Cotruvo, Joseph A
Format Journal Article
LanguageEnglish
Published United States American Chemical Society 15.01.2019
Online AccessGet full text

Cover

Loading…
More Information
Summary:Lanmodulin (LanM) is a high-affinity lanthanide (Ln)-binding protein recently identified in Methylobacterium extorquens, a bacterium that requires Lns for the function of at least two enzymes. LanM possesses four EF-hands, metal coordination motifs generally associated with CaII binding, but it undergoes a metal-dependent conformational change with a 100 million-fold selectivity for LnIIIs and YIII over CaII. Here we present the nuclear magnetic resonance solution structure of LanM complexed with YIII. This structure reveals that LanM features an unusual fusion of adjacent EF-hands, resulting in a compact fold to the best of our knowledge unique among EF-hand-containing proteins. It also supports the importance of an additional carboxylate ligand in contributing to the protein’s picomolar affinity for LnIIIs, and it suggests a role of unusual N i+1–H···N i hydrogen bonds, in which LanM’s unique EF-hand proline residues are engaged, in selective LnIII recognition. This work sets the stage for a detailed mechanistic understanding of LanM’s Ln selectivity, which may inspire new strategies for binding, detecting, and sequestering these technologically important metals.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0006-2960
1520-4995
DOI:10.1021/acs.biochem.8b01019