Penicillin-binding protein folding is dependent on the PrsA peptidyl-prolyl cis-trans isomerase in Bacillus subtilis

Hanne-Leena Hyyryläinen (1) , Bogumila C. Marciniak (2) , Kathleen Dahncke (3) , Milla Pietiäinen (1) , Pascal Courtin (4) , Marika Vitikainen (1) , Raili Seppala (1) , Andreas Otto (3) , Dörte Becher (3) , Marie-Pierre Chapot-Chartier (5) , Oscar P Kuipers (2) , Vesa Pekka Kontinen (6)

1 Department of Infectious Disease Surveillance and Control
2 Department of Molecular Genetics
3 Institute of Microbiology
4 Microbiology
5 Microbiology
6 Department of Infectious Disease Surveillance and Control

The PrsA protein is a membrane-anchored peptidyl-prolyl cis-trans isomerase in Bacillus subtilis and most other gram-positive bacteria. It catalyzes the post-translocational folding of exported proteins and is essential for normal growth of B. subtilis. We studied the mechanism behind this indispensability. We could construct a viable prsA null mutant in the presence of a high concentration of magnesium. Various changes in cell morphology in the absence of PrsA suggested that PrsA is involved in the biosynthesis of the cylindrical lateral wall. Consistently, four penicillin-binding proteins (PBP2a, PBP2b, PBP3 and PBP4) were unstable in the absence of PrsA, while muropeptide analysis revealed a 2% decrease in the peptidoglycan crosslinkage index. Misfolded PBP2a was detected in PrsA-depleted cells, indicating that PrsA is required for the folding of this PBP either directly or indirectly. Furthermore, strongly increased uniform staining of cell wall with a fluorescent vancomycin was observed in the absence of PrsA. We also demonstrated that PrsA is a dimeric or oligomeric protein which is localized at distinct spots organized in a helical pattern along the cell membrane. These results suggest that PrsA is essential for normal growth most probably since PBP folding is dependent on this PPIase.

Mots clés: Life Sciences

Hanne-Leena Hyyryläinen, Bogumila C. Marciniak, Kathleen Dahncke, Milla Pietiäinen, Pascal Courtin, et al.. Penicillin-binding protein folding is dependent on the PrsA peptidyl-prolyl cis-trans isomerase in Bacillus subtilis. Molecular Microbiology, 2010, ⟨10.1111/j.1365-2958.2010.07188.x⟩. ⟨hal-00552636⟩