Genomics of Clostridium taeniosporum, an organism which forms endospores with ribbon-like appendages

Abstract

Clostridium taeniosporum, a non-pathogenic anaerobe closely related to the C. botulinum Group II members, was isolated from Crimean lake silt about 60 years ago. Its endospores are surrounded by an encasement layer which forms a trunk at one spore pole to which about 12–14 large, ribbon-like appendages are attached. The genome consists of one 3,264,813 bp, circular chromosome (with 26.6% GC) and three plasmids. The chromosome contains 2,892 potential protein coding sequences: 2,124 have specific functions, 147 have general functions, 228 are conserved but without known function and 393 are hypothetical based on the fact that no statistically significant orthologs were found. The chromosome also contains 101 genes for stable RNAs, including 7 rRNA clusters. Over 84% of the protein coding sequences and 96% of the stable RNA coding regions are oriented in the same direction as replication. The three known appendage genes are located within a single cluster with five other genes, the protein products of which are closely related, in terms of sequence, to the known appendage proteins. The relatedness of the deduced protein products suggests that all or some of the closely related genes might code for minor appendage proteins or assembly factors. The appendage genes might be unique among the known clostridia; no statistically significant orthologs were found within other clostridial genomes for which sequence data are available. The C. taeniosporum chromosome contains two functional prophages, one Siphoviridae and one Myoviridae, and one defective prophage. Three plasmids of 5.9, 69.7 and 163.1 Kbp are present. These data are expected to contribute to future studies of developmental, structural and evolutionary biology and to potential industrial applications of this organism.

Current Insights on the Diverse Structures and Functions in Bacterial Collagen-like Proteins

“…Clostridium taeniosporum was described as an appendage-forming Clostridia that attaches about 12 large, ribbon-like appendages through a common trunk at one spore pole to a layer outside the coat, called the “encasement”. Unlike the loosely fitting exosporia, the encasement layer fits tightly around the spore. , In C. taeniosporum, fibrils were clearly visible as a hair-like nap along the appendage edge in atomic force microscope (AFM) images.…”

“…Unlike the loosely fitting exosporia, the encasement layer fits tightly around the spore. 87,88 In C. taeniosporum, fibrils were clearly visible as a hair-like nap along the appendage edge in atomic force microscope (AFM) images. Among the four appendage proteins identified in C. taeniosporum spores, a glycoprotein designated GP85 was shown to include a collagen-like region.…”