Extended Data Fig. 4: NifX-like proteins in A. vinelandii.

a, Experimental structure of NifX from the present work. All following models were generated with AlphaFold3. b, The cofactor maturase NifB, with a C-terminal NifX-like domain (purple). c, NafY, the cofactor chaperone that shuttles mature FeMo-co from NifEN to apo-NifDK. The C-terminal NifX-like domain (blue) contains a cofactor-binding histidine. d, VnfX is a NifX-like protein in the vnf gene cluster for V-nitrogenase, supposed to interact with the VnfEN complex, analogous to NifX (teal). e, The two-domain NifY protein has a C-terminal NifX-like domain but lacks the cofactor-binding histidine. f, NafX is a further NifX-like protein of unknown function, lacking the histidine required for cofactor binding.