AlphaFold2 predicted structures of the Porphyromonas gingivalis T9SS components complexes: dimer of PorK-PorN, ring of PorK-PorN, PorM dimer with PorL pentamer, PorK in complex with a dimer of PorM domains 2-4

Type IX secretion system (T9SS)   has been studied mainly in Porphyromonas gingivalis. Among the 18 genes, essential for T9SS function, a group of four, porK-L-M-N  belongs to a co-transcribed operon that expresses the T9SS core membrane complex. The central component of this complex, PorM (or GldM), is anchored in the inner membrane by a trans-membrane helix and interacts through the outer membrane PorK-N complex. There are available atomic structures

PorM complex. Here we report the AlphaFold2 predicted structure of several complexes involving PorK-L-M-N:

• A dimer of  PorK-PorN
• A ring of the PorK-PorN complex
• The PorM dimer in complex with the PorL pentamer,
• PorK in complex with the PorMd1-3 dimer.