owing to the close proximity of its tandem actin-binding domains, fimbrin directs the formation of tightly bundled actin filaments that participate in dynamic processes, including cytokinesis in yeast and host cell invasion by enteropathic bacteria. although fimbrin's involvement in processes like these as well as its role in assembly and regulation of microfilament networks are well documented, there are fewer experimental data describing the overall domain organization of the molecule. klein "et al." (2004) detailed the crystal structure of the "arabidopsis thaliana" and "schizosaccharomyces pombe" fimbrin cores in an attempt to highlight the compact and distinctly asymmetric organization of the fimbrin molecule. this structural study of the fimbrin core represents the first detailed structural description of a functional actin cross-linking protein.