6mi5

Publication Abstract from PubMed

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 Ca(II) binding, but it undergoes a metal-dependent conformational change with a 100 million-fold selectivity for Ln(III)s and Y(III) over Ca(II). Here we present the nuclear magnetic resonance solution structure of LanM complexed with Y(III). 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 Ln(III)s, 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 Ln(III) 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.

Structural Basis for Rare Earth Element Recognition by Methylobacterium extorquens Lanmodulin.,Cook EC, Featherston ER, Showalter SA, Cotruvo JA Jr Biochemistry. 2018 Nov 2. doi: 10.1021/acs.biochem.8b01019. PMID:30352145^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.