title: The role of histone-like protein, Hlp, in Mycobacterium smegmatis dormancy.
abstract: The role of histone-like protein (Hlp) in the development of a dormant state in long-incubated stationary-phase Mycobacterium smegmatis cells was studied in two models: (1) adoption of 'nonculturable' (NC) state, which is reversible due to resuscitation with proteinaceous resuscitation-promoting factor (Rpf) and (2) the formation of morphologically distinct, ovoid resting forms. In the first model, inactivation of the hlp gene resulted in prolongation of culturability of starved cells followed by irreversible nonculturability when mycobacterial cells were unresponsive to resuscitation with Rpf. In the second model, M. smegmatis strain with the inactivated hlp gene was able to form dormant ovoid cells, but they were less resistant to heating and UV radiation than those of wild-type strain. The susceptibility of ovoid cells produced by Delta hlp mutant to these damaging factors was probably due to a less condensed state of DNA, as revealed by fluorescent microscopy and DAPI staining. Evidently, Hlp is essential for cell viability at a later stage of NC dormancy or provides a greater stability of specialized dormant forms.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia. aleksey.anuchin@mail.ru
authors.forename: Aleksey M
authors.initials: AM
authors.lastname: Anuchin
authors.forename: Anna V
authors.initials: AV
authors.lastname: Goncharenko
authors.forename: Galina R
authors.initials: GR
authors.lastname: Demina
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Mulyukin
authors.forename: Dmitry N
authors.initials: DN
authors.lastname: Ostrovsky
authors.forename: Arseny S
authors.initials: AS
authors.lastname: Kaprelyants
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D006358:Hot Temperature; D006801:Humans; D050296:Microbial Viability / Q000528:radiation effects; D020102:Mycobacterium smegmatis / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins