Plastin Family of Actin-Bundling Proteins: Its Functions in
Leukocytes, Neurons, Intestines, and Cancer
Figure 2
Schematic diagram of L-plastin structure. (a) Domain organization of L-plastin. The protein possesses an N-terminal headpiece of ~100 amino acids containing two EF-hand Ca2+-binding motifs and two actin-binding domains (ABDs) consisting of ABD1 (residues 120–379) and ABD2 (residues 394–623), and each ABD contains two calponin-homology (CH) domains. (b) Reconstructed molecular shape of L-plastin. Conformational analyses of L-plastin by X-ray scattering in solution revealed that plastin has a compact globular structure rather than a dumbbell-like shape. It is conceivable that the two ABDs are packed together in an approximately antiparallel arrangement with the N- and C-terminal CH domains (CH1 and CH4) making direct contact as shown in Figure 2(c); that is, , , and correspond to CH1–CH3, CH2–CH4, and CH3-CH4 of the plastin protein, respectively. indicates a putative N-terminal headpiece. See more details in [6, 7]. (c) Possible arrangement of the ABDs (CH1–CH4) of L-plastin in solution without Ca2+.
