Structural highlights
Function
GELA_DICDI F-actin cross-linking protein.SECM_ECOLI Regulates secA expression by translational coupling of the secM secA operon. Ribosomes translating the C-terminal region of secM can disrupt an RNA repressor helix that normally blocks secA translation initiation, derepressing the expression of secA. Translational pausing of secM at Pro-166 under secretion-limiting conditions increases the duration of the disruption and thus increases secA expression. This is controlled by interaction of the secM signal peptide with secA and the translocon, possibly by secA pulling the paused secM out of the ribosome. The arrest sequence (150-FXXXXWIXXXXGIRAGP-166) is sufficient to cause arrest of unrelated proteins. Elongation arrest can be alleviated by mutations in the 23S rRNA or in ribosomal protein L22.
