Non-sporulating ftsZ mutants in Streptomyces coelicolor reveal amino acid residues critical for FtsZ polymerization dynamics.
Författare
Summary, in English
During sporulation of Streptomyces coelicolor, the cytokinetic protein FtsZ is assembled into dozens of regularly spaced Z rings, which orchestrate the division of aerial hyphae into spores. We have previously found that a missense allele of ftsZ, ftsZ17(Spo), primarily affects sporulation septation rather than formation of cross-walls in vegetative mycelium. To clarify what aspect of FtsZ function is compromised in such non-sporulating mutants, we here use a genetic strategy to identify new ftsZ(Spo) alleles and describe how some of the mutations affect the biochemical properties of FtsZ. We have established a system for purification of recombinant untagged S. coelicolor FtsZ, and show that it assembles dynamically into single protofilaments, displays a critical concentration indicative of cooperative assembly, and has a rate of GTP hydrolysis that is substantially higher than that of the closely related Mycobacterium tuberculosis FtsZ. Of the nine isolated ftsZ(Spo) mutations, four affect the interface between the two main subdomains of FtsZ that is implicated in the assembly-induced conformational changes thought to mediate the GTP/GDP-driven cooperative assembly of FtsZ. We find that all these four mutations affect the polymerization behavior of FtsZ in vitro. In addition, at least one ftsZ(Spo) mutation at the longitudinal contact surface between subunits in protofilaments strongly affects formation of polymers in vitro. We conclude that the assembly of Z rings during sporulation of S. coelicolor is highly sensitive to disturbances of FtsZ polymerization, and therefore constitutes an excellent system for analysis of the elusive properties of FtsZ that mediate its characteristic polymerization dynamics.
Publiceringsår
2013
Språk
Engelska
Sidor
890-901
Publikation/Tidskrift/Serie
Microbiology
Volym
159
Issue
Online March 8, 2013
Dokumenttyp
Artikel i tidskrift
Förlag
MAIK Nauka/Interperiodica
Ämne
- Biological Sciences
Status
Published
Forskningsgrupp
- Microbiology Group
ISBN/ISSN/Övrigt
- ISSN: 1465-2080