Rebinding of Tetrahymena 13 S and 21 S dynein ATPases to extracted doublet microtubules. The inner row and outer row dynein arms.

摘要: Ciliary axonemes from Tetrahymena contain a second salt-extractable ATPase distinguishable outer arm 21 S dynein by sedimentation velocity (congruent to 13 S), electrophoretic mobility and substrate specificity. As characterized turbidimetric assay, gel electrophoresis in the presence of sodium dodecyl sulphate, activity electron microscopy, rebinds extracted doublet microtubules. Compared structural-side (ATP-insensitive) binding, which is moderately specific for 24 nm row position, rebinding highly but inner position. However, A subfibre with spacing that coincides triplet radial spokes (24–32-40 periods; 96 repeat). All major protein components present or fractions rebind doublets under conditions both restore activate activity. Unlike active-side (ATP-sensitive) rebound dynein, completely insensitive dissociation ATP-vanadate does not independently decorate B subfibre. The saturation profile exhibits lack cooperativity between binding events (h = 1.0) similar dynein. At low S/doublet stoichiometry there no measureable competition dyneins sites on lattice, although at saturating concentrations blocked completely.