SB; MB and KAK participated in the design of the study and coordination and helped to draft the manuscript. PLP and TKJ performed the histopathology of the RG7112 cost samples and scored the degree of NEC in each tissue sample. CP did the statistical analysis. JK participated in collecting the samples. LM carried out the sequencing and sequence analysis and participated in writing the manuscript. All authors read and approved the final manuscript.”
“Background Staphylococcus aureus is a frequent colonizer of the human body as well as a serious human pathogen. It is known for its adaptability to diverse

environments. It can cope with stress factors and acquire resistances to antibiotics GSK923295 cost thus rendering treatment difficult. S. aureus can cause a wide range of infections, mainly due to an impressive arsenal of virulence determinants

comprising cell surface components and excreted factors interacting with the host C646 molecular weight system. Transport of proteins to the cell surface and secretion to the extracellular space is mediated through different transport systems [1] of which the general protein secretion system Sec plays a prominent role in protein export and membrane insertion. Sec-mediated translocation has best been studied in Escherichia coli and is catalyzed by the essential SecYEG protein complex (reviewed in [2]). The motor ATPase SecA or a translating ribosome is believed to promote protein export by driving the substrate in an unfolded conformation through the SecYEG channel. The accessory SecDF-YajC complex facilitates protein export and membrane protein insertion efficiency in vivo [3], possibly via the control of SecA cycling [4]. The large exoplasmic loops of the integral membrane proteins SecD and SecF have been shown to be required for increasing protein translocation by a yet unknown mode of action Bay 11-7085 [5]. While secDF disruption leads to a cold-sensitive phenotype and defects in protein translocation [6], the absence of YajC, which interacts with SecDF, causes only a weak phenotype [7]. SecYEG

has been shown to interact with the SecDF-YajC complex [8]. YidC, a protein that is proposed to mediate membrane integration and the assembly of multimeric complexes, can also interact with SecDF-YajC to take over SecYEG-dependent membrane proteins [9]. Data on the S. aureus Sec system is scarce: SecA and SecY have been shown to be important, respectively essential, for growth by using antisense RNA [10]. Deletion of secG resulted in an altered composition of the extracellular proteome, which was aggravated in a secG secY2 double mutant [11]. Deletion of secY2 alone, which together with secA2 belongs to the accessory Sec system [12], did not show any effect on protein translocation. As in the Gram-positive bacterium Bacillus subtilis, in S.