Polymerizes into bundles of filaments, forming a helix with a filament width of 5.5 nm and an axial repeating unit of 5.5 nm. Polymerization of Ta0583 requires NTP and is optimal with ATP, but GTP, UTP, CTP, and even the deoxy form of NTP can also support the polymerization reaction. Nucleoside diphosphate or AMP-PNP does not support polymerization. Optimum pH is 4.5-5.5 for the polymerization reaction. Optimum temperature is 50-56 degrees Celsius for the polymerization reaction. Mg(2+) is required for polymerization. 4 mM MgCl(2) is sufficient to enhance the polymerization; however, higher concentrations of MgCl(2) suppresses polymerization. Polymerization is also suppressed by addition of NaCl, KCl or CaCl(2), with half suppression by about 100 mM, 10 mM and 18 mM, respectively. Belongs to the thermophilic archaeal actin family.