Isocitrate binds to the itaconic acid-responsive LysR-type transcriptional regulator RipR in Salmonella pathogenesis.

Macrophages produce itaconic acid in phagosomes in response to bacterial cell wall component lipopolysaccharide to eliminate invading pathogenic bacteria. Itaconic acid competitively inhibits the first enzyme of the bacterial glyoxylate cycle. To overcome itaconic acid stress, bacteria employ the bacterial LysR-type transcriptional regulator RipR.

Crystal structure of the phage-encoded N-acetyltransferase in complex with acetyl-CoA, revealing a novel dimeric arrangement.

Bacteriophages employ diverse mechanisms to facilitate the proliferation of bacteriophages. The Salmonella-infecting phage SPN3US contains a putative N-acetyltransferase, which is widely found in bacteriophages. However, due to low sequence similarity to the N-acetyltransferases from bacteria and eukaryotic cells, the structure and function of phage-encoded acetyltransferases are mainly unknown.

Structure and Function of the Autolysin SagA in the Type IV Secretion System of .

A recent genetic study with revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains.