Dataset Information

Characterization of McuB, a periplasmic chaperone-like protein involved in the assembly of Myxococcus spore coat.

ABSTRACT: The MXAN3885 to -3882 gene locus cluster (designated here mcuABCD) of Myxococcus xanthus encodes a member of the archaic chaperone-usher (CU) systems that functions in spore coat formation. We show here that McuD, a putative spore coat protein, affects cellular accumulation and cell surface localization of the spore coat protein McuA. We previously reported that genetic disruption of the putative usher McuC nearly eliminates surface display of McuA and show here that lack of the periplasmic chaperone-like protein McuB, which forms a complex with McuA, has a similar effect. Deletion mutation confirms that the G1 ? strand of McuB is absolutely essential for the stability and secretion of McuA. Site-directed mutagenesis identified two additional alternating hydrophobic residues Ile113 and Val115, together with the highly conserved proline within the G1 strand, as critical residues for chaperone function. These findings suggest that the assembly proteins McuB and McuC mediate the transport of McuA onto the cell surface and that McuA may interact with another spore coat protein, McuD, for its secretion. Importantly, although our data argue that the M. xanthus CU system is likely to use the basic principle of donor strand complementation (DSC), as in the cases of classical CU pathways, to promote folding and stabilization of the structural subunit(s), the periplasmic chaperone McuB appears to exhibit structural variation in mediating chaperone-subunit interaction.

SUBMITTER: Zhu W

PROVIDER: S-EPMC3697529 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Characterization of McuB, a periplasmic chaperone-like protein involved in the assembly of Myxococcus spore coat.

Zhu Wei W Wu Miaomiao M Cao Shanshan S Peng Yongxing Y Mao Xiaohua X

Journal of bacteriology 20130510 13

The MXAN3885 to -3882 gene locus cluster (designated here mcuABCD) of Myxococcus xanthus encodes a member of the archaic chaperone-usher (CU) systems that functions in spore coat formation. We show here that McuD, a putative spore coat protein, affects cellular accumulation and cell surface localization of the spore coat protein McuA. We previously reported that genetic disruption of the putative usher McuC nearly eliminates surface display of McuA and show here that lack of the periplasmic chap ...[more]

PMID: 23667231

Similar Datasets

Project description:At a late stage in spore development in Bacillus subtilis, the mother cell directs synthesis of a layer of peptidoglycan known as the cortex between the two forespore membranes, as well as the assembly of a protective protein coat at the surface of the forespore outer membrane. SafA, the key determinant of inner coat assembly, is first recruited to the surface of the developing spore and then encases the spore under the control of the morphogenetic protein SpoVID. SafA has a LysM peptidoglycan-binding domain, SafALysM, and localizes to the cortex-coat interface in mature spores. SafALysM is followed by a region, A, required for an interaction with SpoVID and encasement. We now show that residues D10 and N30 in SafALysM, while involved in the interaction with peptidoglycan, are also required for the interaction with SpoVID and encasement. We further show that single alanine substitutions on residues S11, L12, and I39 of SafALysM that strongly impair binding to purified cortex peptidoglycan affect a later stage in the localization of SafA that is also dependent on the activity of SpoVE, a transglycosylase required for cortex formation. The assembly of SafA thus involves sequential protein-protein and protein-peptidoglycan interactions, mediated by the LysM domain, which are required first for encasement then for the final localization of the protein in mature spores.IMPORTANCE Bacillus subtilis spores are encased in a multiprotein coat that surrounds an underlying peptidoglycan layer, the cortex. How the connection between the two layers is enforced is not well established. Here, we elucidate the role of the peptidoglycan-binding LysM domain, present in two proteins, SafA and SpoVID, that govern the localization of additional proteins to the coat. We found that SafALysM is a protein-protein interaction module during the early stages of coat assembly and a cortex-binding module at late stages in morphogenesis, with the cortex-binding function promoting a tight connection between the cortex and the coat. In contrast, SpoVIDLysM functions only as a protein-protein interaction domain that targets SpoVID to the spore surface at the onset of coat assembly.

Dataset Information

Characterization of McuB, a periplasmic chaperone-like protein involved in the assembly of Myxococcus spore coat.

Publications

Characterization of McuB, a periplasmic chaperone-like protein involved in the assembly of Myxococcus spore coat.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets