Catalyzes the NADH-dependent reductive condensation of alpha-ketoglutarate to the intermediate formed by the adjacently encoded enzyme CntL, namely (2S)-2-amino-4-{[(1S)-1-carboxy-2-(1H-imidazol-4-yl)ethyl]amino}butanoate, leading to the production of pseudopaline. This is the last step in the biosynthesis of the metallophore pseudopaline, which is involved in the acquisition of nickel and zinc, and thus enables bacterial growth inside the host, where metal access is limited. Therefore, this enzyme probably contributes to Pseudomonas virulence. Can use neither pyruvate nor NADPH in place of alpha-ketoglutarate and NADH, respectively. H2O + NAD(+) + pseudopaline = (2S)-2-amino-4-{[(1S)-1-carboxy-2-(1H-imidazol-4-yl)ethyl]amino}butanoate + 2-oxoglutarate + H(+) + NADH Homodimer (By similarity). Interacts with CntL (PubMed:29214991). Is part of the operon cntOLMI that is negatively regulated by zinc level through the Zur repressor, which leads to transcriptional activation of this operon under zinc depletion. Belongs to the staphylopine dehydrogenase family.