title: Resuscitation-promoting factors are cell wall-lytic enzymes with important roles in the germination and growth of Streptomyces coelicolor.
abstract: Dormancy is a common strategy adopted by bacterial cells as a means of surviving adverse environmental conditions. For Streptomyces bacteria, this involves developing chains of dormant exospores that extend away from the colony surface. Both spore formation and subsequent spore germination are tightly controlled processes, and while significant progress has been made in understanding the underlying regulatory and enzymatic bases for these, there are still significant gaps in our understanding. One class of proteins with a potential role in spore-associated processes are the so-called resuscitation-promoting factors, or Rpfs, which in other actinobacteria are needed to restore active growth to dormant cell populations. The model species Streptomyces coelicolor encodes five Rpf proteins (RpfA to RfpE), and here we show that these proteins have overlapping functions during growth. Collectively, the S. coelicolor Rpfs promote spore germination and are critical for growth under nutrient-limiting conditions. Previous studies have revealed structural similarities between the Rpf domain and lysozyme, and our in vitro biochemical assays revealed various levels of peptidoglycan cleavage capabilities for each of these five Streptomyces enzymes. Peptidoglycan remodeling by enzymes such as these must be stringently governed so as to retain the structural integrity of the cell wall. Our results suggest that one of the Rpfs, RpfB, is subject to a unique mode of enzymatic autoregulation, mediated by a domain of previously unknown function (DUF348) located within the N terminus of the protein; removal of this domain led to significantly enhanced peptidoglycan cleavage.
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Sexton
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Renée J
authors.initials: RJ
authors.lastname: St-Onge
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Haiser
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mary R
authors.initials: MR
authors.lastname: Yousef
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Lauren
authors.initials: L
authors.lastname: Brady
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Chan
authors.initials: C
authors.lastname: Gao
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Leonard
authors.affiliation: Department of Biology and M. G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada melliot@mcmaster.ca.
authors.forename: Marie A
authors.initials: MA
authors.lastname: Elliot
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010457:Peptidoglycan / Q000378:metabolism; D016415:Sequence Alignment; D013171:Spores, Bacterial / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D016207:Cytokines; D010457:Peptidoglycan; C113704:resuscitation-promoting factor, bacteria