(ii) The MptS protein is produced during the late stages of growth, (iii) accumulates within spores, (iv) functions as an active enzyme that releases inorganic phosphate from an artificial model substrate, (v) is required for spore dormancy and (vi) MptS supports the interaction amongst Streptomyces lividans spores with conidia of the fungus Aspergillus
proliferans. We discuss the possible role(s) of MptS-dependent enzymatic activity and the implications for spore biology. “
“Molecular Selleckchem Seliciclib chaperones are defined as proteins that assist the noncovalent assembly of other protein-containing structures in vivo, but which are not components of these structures when they are carrying out their normal biological functions. There are numerous families of protein ABT-199 mw that fit this definition of molecular chaperones, the most ubiquitous of which are the chaperonins and the Hsp70 families, both of which are required for the correct folding of nascent polypeptide chains and thus essential genes for cell viability. The groE genes of Escherichia coli were the first chaperonin genes to be discovered, within an operon comprising two genes, groEL and groES, that function
together in the correct folding of nascent polypeptide chains. The identification of multiple groEL genes in mycobacteria, only one of which is operon-encoded with a groES gene, has led to debate about the functions of their encoded proteins, especially as the essential copies are surprisingly often not the operon-encoded genes. Comparisons Thymidine kinase of these protein sequences reveals a consistent functional homology and identifies an actinomycete-specific chaperonin family, which may chaperone the folding of enzymes involved in mycolic acid synthesis and thus provide a unique target
for the development of a new class of broad-spectrum antimycobacterial drugs. Mycobacteria are aerobic acid-fast bacteria, ubiquitous in the environment, which belong to the phylum Actinobacteria. More than 125 mycobacterial species have now been identified, about a third of which are potentially pathogenic to humans. These include pathogens of global importance such as Mycobacterium tuberculosis and Mycobacterium leprae, as well as a diverse group of nontuberculous mycobacteria (Wilson, 2008). The global burden of TB was estimated by the WHO in 2011 as 8.7 million new cases and an annual mortality of 1.4 million deaths, a third of which are in HIV-positive individuals where the emergence of multidrug-resistant strains is of particular concern (WHO, 2012).