Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	Mechanism of actin thin filament pointed-end elongation by leiomodin.
Journal, issue, pages	Nat Commun, Vol. 17, Issue 1, Year 2026
Publish date	Jul 20, 2026
Authors	Shayna B Brotzman / Nicholas J Palmer / Malgorzata Boczkowska / Roberto Dominguez /
PubMed Abstract	In non-muscle cells, actin filaments exhibit variable lengths and rapid turnover, with subunits adding primarily at the barbed end. The situation is strikingly different in striated muscle ...In non-muscle cells, actin filaments exhibit variable lengths and rapid turnover, with subunits adding primarily at the barbed end. The situation is strikingly different in striated muscle sarcomeres, where despite rapid turnover, actin thin filaments exhibit uniform length and exchange subunits primarily at the pointed end. This filament length uniformity is tightly regulated by several proteins, including the molecular ruler nebulin in skeletal muscle and the barbed- and pointed-end capping proteins CapZ and tropomodulin (Tmod) in both skeletal and cardiac muscles. Recent studies in cells and animal models have identified leiomodin-2 (Lmod2) as an additional regulator proposed to promote pointed-end elongation to maintain thin filament length. This activity would make leiomodin the only known eukaryotic factor to drive pointed-end elongation, yet its molecular mechanism remains unresolved. Here, we present a series of cryo-electron microscopy structures that support a stepwise elongation mechanism in which two Lmod2 molecules alternate at the pointed end while recruiting actin monomers. These findings establish the molecular basis of pointed-end elongation in muscle sarcomeres and provide a framework for understanding mutations in Lmod2 that cause dilated cardiomyopathy.
External links	Nat Commun / PubMed:42477379 / PubMed Central
Methods	EM (single particle) / EM (helical sym.)
Resolution	2.06 - 3.96 Å
Structure data	EMDB-74997: Free pointed end of F-actin Method: EM (single particle) / Resolution: 3.18 Å 74998 9zzi EMDB-74998, PDB-9zzi: Cryo-EM structure of F-actin in the ADP state Method: EM (helical sym.) / Resolution: 2.06 Å EMDB-75000: Consensus map for One Lmod2 at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.39 Å EMDB-75001: Local refinement of Lmod2 and the two terminal pointed end actins for One Lmod2 at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.5 Å EMDB-75002: Local refinement of bottom five actins for One Lmod2 at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.28 Å 75003 9zzj EMDB-75003, PDB-9zzj: One Lmod2 at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.28 Å EMDB-75006: Consensus map for Two Lmod2s and incoming actin at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.56 Å EMDB-75008: Local refinement of both Lmod2s, incoming actin, and the two terminal pointed end actins for Two Lmod2s and incoming actin at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.96 Å EMDB-75009: Local refinement of the bottom five actins for Two Lmod2s and incoming actin at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.42 Å 75010 9zzm EMDB-75010, PDB-9zzm: Two Lmod2s and incoming actin at the pointed end of F-actin Method: EM (single particle) / Resolution: 3.56 Å
Chemicals	ChemComp-ADP: ADENOSINE-5'-DIPHOSPHATE / ADP, energy-carrying moleculeYM ChemComp-MG: Unknown entry ChemComp-HOH: WATER ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP, energy-carrying moleculeYM
Source	oryctolagus cuniculus (rabbit) homo sapiens (human)
Keywords	STRUCTURAL PROTEIN / actin / F-actin / Lmod2 / leiomodin