So far, observation of NOS or SONOS bond formation shows little dependence to the environment. When it was first reported in the transaldolase enzyme of Neisseria gonorrhoeae, 4 the possible action of a near-lying glutamic acid residue (E93) was considered, but ultimately not confirmed. With the observation of the bond in a wide variety of locations, hydrophobic to hydrophylic, exposed or buried, intra-and inter-molecular, there is little in common between the identified neighbouring residues, strongly suggesting that the general mechanism of formation does not require the preference of a third specific reaction partner.