tuberculosis H37Rv. ABC transporter proteins are found in both eukaryotes and prokaryotes and constitute a large super family of multi-subunit permeases that transport various molecules (ions, amino acids, click here peptides, antibiotics, polysaccharides, proteins, etc.) across biological membranes, with a relative specificity for a given substrate [43]. They consist of two hydrophobic membrane spanning domains (MSDs) associated with two cytoplasmic

nucleotide binding domains (NBDs) [44–46]. They are classified as importers and exporters depending on the direction of translocation of their substrate [47]. Importers are found exclusively in prokaryotes and are involved in the uptake of extracellular molecules [48]. Exporters are found in both prokaryotes and eukaryotes, where they export molecules from the cytoplasm [49]. Taken together, the observation of three transporter proteins with higher PRN1371 supplier abundance in M. tuberculosis H37Rv may suggest a significant role of these proteins in the overall transport of nutrition by the bacilli, influencing its chances for survival, rendering the two strains, although highly similar, in different physiological

states that make one of them more fit for survival in host cells and consequently more pathogenic. On the other hand, 10 membrane-associated proteins were observed with >5x or higher relative abundance in M. tuberculosis H37Ra. Only three of those (Rv0014c, Rv0070 and Rv1030), were proposed to have a biological function, the role of the rest is yet to be determined. The gene encoding transmembrane serine/threonine-protein kinase pknB (Rv0014c) protein was found to be essential for mycobacterial growth. This protein is thought to be involved in signal transduction via phosphorylation. PknB has been shown to be a substrate for phosphoserine/threonine phosphatase PstP (Rv0018c), which is also up-regulated in M. tuberculosis H37Ra, and its kinase activity is affected by PstP -mediated dephosphorylation. PknB and phosphoserine/threonine phosphatase PstP (Rv0018c) may act as a Etofibrate functional pair in vivo to control mycobacterial cell growth [50, 51].

The putative gene GlyA2 (Rv0070) has been proposed to encode for the enzyme buy AZD1390 serine hydroxymethyltransferase (SHMT), up-regulated in M. tuberculosis H37Ra, is a pyridoxyl 5- phosphate (PLP)-dependent enzyme. The SHMT reaction plays a major role in cell physiology as it is considered to be a key enzyme in the pathway for interconversion of folate coenzymes that provide almost exclusively one-carbon fragments for the biosynthesis of a variety of end products such as DNA, RNA, ubiquinone, methionine, etc. [52]. The physiological role of SHMT is the reversible interconversion of serine to glycine. From the genome analysis of M. tuberculosis, there is an additional SHMT gene (GlyA1, Rv1093); the relative abundance of this enzyme is similar in both strains.