title: Formation and composition of the Bacillus anthracis endospore.
abstract: The endospores of Bacillus anthracis are the infectious particles of anthrax. Spores are dormant bacterial morphotypes able to withstand harsh environments for decades, which contributes to their ability to be formulated and dispersed as a biological weapon. We monitored gene expression in B. anthracis during growth and sporulation using full genome DNA microarrays and matched the results against a comprehensive analysis of the mature anthrax spore proteome. A large portion (approximately 36%) of the B. anthracis genome is regulated in a growth phase-dependent manner, and this regulation is marked by five distinct waves of gene expression as cells proceed from exponential growth through sporulation. The identities of more than 750 proteins present in the spore were determined by multidimensional chromatography and tandem mass spectrometry. Comparison of data sets revealed that while the genes responsible for assembly and maturation of the spore are tightly regulated in discrete stages, many of the components ultimately found in the spore are expressed throughout and even before sporulation, suggesting that gene expression during sporulation may be mainly related to the physical construction of the spore, rather than synthesis of eventual spore content. The spore also contains an assortment of specialized, but not obviously related, metabolic and protective proteins. These findings contribute to our understanding of spore formation and function and will be useful in the detection, prevention, and early treatment of anthrax. This study also highlights the complementary nature of genomic and proteomic analyses and the benefits of combining these approaches in a single study.
authors.affiliation: Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Liu
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Bergman
authors.forename: Brendan
authors.initials: B
authors.lastname: Thomason
authors.forename: Shamira
authors.initials: S
authors.lastname: Shallom
authors.forename: Alyson
authors.initials: A
authors.lastname: Hazen
authors.forename: Joseph
authors.initials: J
authors.lastname: Crossno
authors.forename: David A
authors.initials: DA
authors.lastname: Rasko
authors.forename: Jacques
authors.initials: J
authors.lastname: Ravel
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Read
authors.forename: Scott N
authors.initials: SN
authors.lastname: Peterson
authors.forename: John
authors.initials: J
authors.lastname: Yates
authors.forename: Philip C
authors.initials: PC
authors.lastname: Hanna
mesh_terms: D001408:Bacillus anthracis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome; D013171:Spores, Bacterial / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D020543:Proteome