Fig. 7.

Model of the Csd5 H. pylori cell shape promoting protein complex.

Csd5 protein is anchored in the inner membrane where it mediates interactions between a putative cytoskeletal bactofilin CcmA, the PG precursor synthase MurF (D-Ala-D-Ala ligase), and the rotary F₁F_O ATP synthase. The C-terminal SH3 domain interacts with peptidoglycan in the periplasm and links Csd5 to cytoplasmic cell shape and cell elongation factors essential for helical shape (CcmA) and growth (MurF). OM (outer membrane), IM (inner membrane), PG (peptidoglycan), NT (N-terminal), TM (transmembrane), DO (disordered). The PG cell wall is depicted with alternating red (N-acetylmuramic acid) and blue (N-acetylglucosamine) octagons. meso-diaminopimelic acid (m-DAP;green circles) in the PG peptide stems (white circles).