The genome and antigen proteome analysis of Spiroplasma mirum

Abstract

Spiroplasma mirum, small motile wall-less bacteria, was originally isolated from a rabbit tick and had the ability to infect newborn mice and caused cataracts. In this study, the whole genome and antigen proteins of S. mirum were comparative analyzed and investigated. Glycolysis, pentose phosphate pathway, arginine metabolism, nucleotide biosynthesis, and citrate fermentation were found in S. mirum, while trichloroacetic acid, fatty acids metabolism, phospholipid biosynthesis, terpenoid biosynthesis, lactose-specific PTS, and cofactors synthesis were completely absent. The Sec systems of S. mirum consist of SecA, SecE, SecDF, SecG, SecY, and YidC. Signal peptidase II was identified in S. mirum, but no signal peptidase I. The relative gene order in S. mirum is largely conserved. Genome analysis of available species in Mollicutes revealed that they shared only 84 proteins. S. mirum genome has 381 pseudogenes, accounting for 31.6% of total protein-coding genes. This is the evidence that spiroplasma genome is under an ongoing genome reduction. Immunoproteomics, a new scientific technique combining proteomics and immunological analytical methods, provided the direction of our research on S. mirum. We identified 49 proteins and 11 proteins (9 proteins in common) in S. mirum by anti-S. mirum serum and negative serum, respectively. Forty proteins in S. mirum were identified in relation to the virulence. All these proteins may play key roles in the pathogeny and can be used in the future for diagnoses and prevention.

Loss to gain: pseudogenes in microorganisms, focusing on eubacteria, and their biological significance

“…A total of 95 and 101 pseudogene candidates in whole-genome of Escherichia coli ( E. coli ) strains K-12 and O157, respectively, were reported (Homma et al 2002 ). Besides, pseudogenes sequences have been observed within the genome of other bacteria species, such as Brucella (Bialer et al 2021 ), Shigella (Cervantes-Rivera et al 2020 ), Spirochete (Liu et al 2022a ), Staphylococcus (Chieffi et al 2020 ), and Fungi (Oh et al 2021 ; Shimizu et al 2021 ). In addition, abundant pseudogenes have also been found in the obligate parasite Mycobacterium leprae ( M. leprae ) (Cole et al 2001 ; Silva et al 2022 ), Rickettsia (Andersson et al 1998 ; Liu et al 2004 ), and Anaplasma (Lin et al 2023 ).…”

Wild communities ofMorphobutterflies revealSpiroplasmaendosymbiont with inflated genome size and peculiar evolution

“…Spiroplasma are associated with a large variety of hosts, and their genomes appear highly eroded with reduced metabolic capacities, high proportion of pseudogenes, and elevated evolutionary rates(Gerth et al 2021; Liu et al 2022). In Drosophila , the prevalence of Spiroplasma among natural population is generally low (Watts et al 2009; Haselkorn 2010), but in some cases, the fitness advantages brought to their hosts, such as protection against parasitic nematodes, can make it more common (Jaenike et al 2010).…”