second calponin homology (CH) domain found in the Arabidopsis thaliana fimbrin family
The Arabidopsis thaliana fimbrin (AtFIM) family includes fimbrin-1, -2, -3, -4, and -5, which cross-link actin filaments (F-actin) in a calcium independent manner. They stabilize and prevent F-actin depolymerization mediated by profilin. They act as key regulators of actin cytoarchitecture, and are probably involved in the cell cycle, cell division, cell elongation, and cytoplasmic tractus. AtFIM5 is an actin bundling factor that is required for pollen germination and pollen tube growth. Members of this family contain four copies of the CH domain. This model corresponds to the second CH domain. CH domains are actin filament (F-actin) binding motifs.