Extended Data Fig. 8: Interactions of FtsQ with FtsK.
From: Cryo-EM structure of the bacterial divisome core complex and antibiotic target FtsWIQBL
a) AlphaFold2 model of E. coli FtsWIQBL + FtsK N-terminal domain (residues 1-222; FtsK1–222, grey), showing a predicted interaction between FtsQPOTRA and a periplasmic loop from FtsK (FtsKW51-H57). b) Co-evolutionary coupling analysis calculated with EVcouplings36 finds six out of the ten residue pairs located between FtsQPOTRA and FtsKW51-H57 in the AF2 model in a): FtsQV109 – FtsKW56 (blue), FtsQQ96 – FtsKT54 (dark blue), FtsQS110 – FtsKQ53 (gray), FtsQV111 – FtsKT54 (dark blue), FtsQR112 – FtsKQ53 (grey), and FtsQK113-FtsKS52 (blue). c) Sequence conservation analysis (calculated using ConSurf webserver61) of the same area shows that the β-strands of FtsQ and FtsKW51-H57 that are predicted to interact are highly conserved. Amino acid residues that abolish FtsQ localisation (which is dependent on FtsK septum localisation in cells) when mutated are shown as sticks and are labelled10. d) Size-exclusion trace and SDS-PAGE gel of the co-expression and purification of E. coli FtsQ and FtsK1–222 shows clear co-migration of the proteins.
