Structural and functional insights of itaconyl‐CoA hydratase from Pseudomonas aeruginosa highlight a novel N‐terminal hotdog fold

Itaconyl‐CoA hydratase in Pseudomonas aeruginosa ( Pa Ich) converts itaconyl‐CoA to ( S )‐citramalyl‐CoA upon addition of a water molecule, a part of an itaconate catabolic pathway in virulent organisms required for their survival in humans host cells. Crystal structure analysis of Pa Ich showed that a unique N‐terminal hotdog fold containing a 4‐residue short helical segment α3‐, named as an “eaten sausage”, followed by a flexible loop region slipped away from the conserved β‐sheet scaffold, whereas the C‐terminal hotdog fold is similar to all MaoC. A conserved hydratase motif with catalytic residues provides mechanistic insights into catalysis, and existence of a longer substrate binding tunnel may suggest the binding of longer CoA derivatives.