Similarly, Hales et al. (1998) reported the existence of two differently sized flagellin gene sequences (1.4 and 1.0 kbp) in strains of B. cepacia. These authors also revealed that the strains containing the larger flagellin gene had flagella with selleck relatively greater diameters. The three-dimensional structures of the type I and II flagellins in the Actinoplanes strains were predicted using SWISS-MODEL with a template structure (PDB ID
Code: 3a5x). Interestingly, each of the structures differs most markedly at the region of the knob-like projection, which has been reported to contribute to stabilizing the conformation of the flagellin protein and flagellum fibers (Malapaka et al., 2007). In addition, the type II flagellin had a relatively compact structure that may decrease the mechanical stability of parts of flagellum. This study only observed the type II flagellin in four of the Actinoplanes strains tested, all of which are considered to be motile actinomycetes (Stackebrandt & Kroppenstedt, 1987; Matsumoto et al., 2000). In contrast, the structure of the inner and outer core regions were well conserved in both flagellin proteins. These conserved structures contained the N- and C-terminal regions. The phylogenetic http://www.selleckchem.com/products/BIBF1120.html analysis was performed using the N-terminal amino acid
sequences (115 aa) of flagellin from 17 Actinoplanes species (Fig. 3). The phylogenetic tree showed that the Actinoplanes species formed three clusters, and that some of these relationships were well correlated with analyses obtained using 16S rRNA data. A. consettensis and A. humidus both had highly conserved N-terminal flagellin sequences (aa similarity of 99.3%), and the central and C-terminal regions were also similar. Furthermore, these two strains showed 100% similarity in the 16S rRNA analysis. On the other hand, both species were well characterized by a numerical taxonomical approach, and were established as distinct species without genotypic data. Until now, a polyphasic taxonomic approach including genotypic analysis is believed to determine the taxonomic position of prokaryotic microorganisms. Therefore, these two species should be clarifying
the taxonomic position using genotypic characterization. The observation that A. auranticolor did not cluster with tuclazepam the other members of Actinoplanes in this study may have arisen due to horizontal transfer (Wassenaar et al., 1995; Liu & Ochman, 2007). The differences in the size of flagellin gene, and those revealed in the phylogenetic analysis imply that the N-terminal region of the flagellin gene was useful for phylogeny or evolutionary study in the genus Actiniplanes. However, it is not yet known why organisms with the type II flagellin have lost the knob-like projection on the flagella. In addition, further flagellin gene sequencing of non-Actinoplanes species are required to discuss the evolutional distribution of flagellar gene in actinomycetes.