lanM Gene Review Notes

Key findings from literature:

Primary function: Lanthanide-binding protein

• PMID:30351021: LanM is a highly selective lanthanide(III)-binding protein with 100 million-fold selectivity for La(3+) over Ca(2+). Undergoes conformational change from disordered to ordered state in response to picomolar concentrations of all LnIII (Ln = La-Lu, Y). Contains four EF-hand motifs with unique proline residues.

Structural insights:

• PMID:30352145: NMR structure reveals unusual fusion of adjacent EF-hands, resulting in compact fold unique among EF-hand proteins. Features unusual N i+1-H···N i hydrogen bonds involving unique EF-hand proline residues for selective LnIII recognition.

Biotechnology applications:

• PMID:32686425: Demonstrated universal selectivity for REEs against non-REEs. Retains REE binding down to pH 2.5, withstands temperatures up to 95°C, and tolerates molar amounts of competing non-REE metals. Successfully applied to industrial feedstocks (coal, electronic waste).

Recent advances:

• PMID:37259003: Shows Hans-LanM variant with enhanced RE separation capacity and oligomeric state sensitive to RE ionic radius. Demonstrates natural diversity of selective lanthanide recognition motifs.

Biological context:

• Found in methylotrophic bacterium Methylorubrum extorquens
• Lanthanides are essential cofactors for PQQ-dependent alcohol dehydrogenases in methylotrophs
• Periplasmic protein likely involved in lanthanide transport
• Has four EF-hand domains (unusual for lanthanide vs calcium selectivity)

Functional significance:

• Picomolar affinity for lanthanides
• Conformational sensor for rare earth elements
• Selective metal transport in periplasm
• Part of rare earth element utilization machinery in methylotrophs