User:MariaMeacham/Symbiobacterium thermophilum

Genome Structure
Characteristics of S. thermophilum such as the production of tryptophanase and β-tyrosinase, the cell surface structure, and a negative gram stain results indicate that the bacteria is Gram-negative. However, the sequence of 16S rRNA gene led to the complete phylogenic analysis of S. thermophilum, concluding it was in fact Gram-positive. High-G+C content (68.7%) along with its Gram stain results indicates that S. thermophilum belongs to the Actinomyces phylum, but the genome and proteins are more closely related to the Firmicutes, a Gram-positive phylum with low-G+C content. S. thermophilum further defies the knowledge that endospore forming genes are unique to the Bacillus-Clostridium group, showing genes involved in the formation of endospores. Sequencing of proteins proved biological roles in 2,082 of the 3,338 CDSs. The genome of S. thermophilum is not even partially alike other prokaryotic genomes sequenced at this point in time, as indicated by a CDS similarity matrix search.

Cell Structure
Although Gram staining S. thermophilum shows a negative lab result, there are key Gram-negative membrane biosynthesis proteins that it lacks, such as LPS:glycosyltransferase and polysaccharide transporters. Instead, the cell structure of S. thermophilum includes proteins STH61, 969, 1321, 2197, 2492, and 3168 which are associated with the enveloped S-layer bacteria. The bacillus shape of S. thermophilum cells may be caused by the mreBCD (STH372-4) gene, located adjacent to the min locus. Although it has no flagella, the genome of S. thermophilum does include a flagella biosynthesis gene cluster. S. thermophilum is found to produce endospores in specific conditions. There is less research on the spore-like structure of S. thermophilum as it is the rarer form.