4APW

Alp12 filament structure

Summary for 4APW

• Entry DOI: 10.2210/pdb4apw/pdb
• EMDB information: 2068
• Descriptor: ALP12 (1 entity in total)
• Functional Keywords: structural protein, alp12, actin-like protein
• Biological source: CLOSTRIDIUM TETANI
• Total number of polymer chains: 16
• Total formula weight: 591871.25

Authors

Popp, D.,Narita, A.,Lee, L.J.,Ghoshdastider, U.,Xue, B.,Srinivasan, R.,Balasubramanian, M.K.,Tanaka, T.,Robinson, R.C. (deposition date: 2012-04-06, release date: 2012-05-16, Last modification date: 2024-05-08)

Primary citation

Popp, D.,Narita, A.,Lee, L.J.,Ghoshdastider, U.,Xue, B.,Srinivasan, R.,Balasubramanian, M.K.,Tanaka, T.,Robinson, R.C.
Novel Actin-Like Filament Structure from Clostridium Tetani.
J.Biol.Chem., 287:21121-, 2012

PubMed Abstract: Eukaryotic F-actin is constructed from two protofilaments that gently wind around each other to form a helical polymer. Several bacterial actin-like proteins (Alps) are also known to form F-actin-like helical arrangements from two protofilaments, yet with varied helical geometries. Here, we report a unique filament architecture of Alp12 from Clostridium tetani that is constructed from four protofilaments. Through fitting of an Alp12 monomer homology model into the electron microscopy data, the filament was determined to be constructed from two antiparallel strands, each composed of two parallel protofilaments. These four protofilaments form an open helical cylinder separated by a wide cleft. The molecular interactions within single protofilaments are similar to F-actin, yet interactions between protofilaments differ from those in F-actin. The filament structure and assembly and disassembly kinetics suggest Alp12 to be a dynamically unstable force-generating motor involved in segregating the pE88 plasmid, which encodes the lethal tetanus toxin, and thus a potential target for drug design. Alp12 can be repeatedly cycled between states of polymerization and dissociation, making it a novel candidate for incorporation into fuel-propelled nanobiopolymer machines.

PubMed: 22514279
DOI: 10.1074/JBC.M112.341016

Experimental method

ELECTRON MICROSCOPY (19.7 Å)