The Paracoccus denitrificans NarK-like nitrate and nitrite transporters-probing nitrate uptake and nitrate/nitrite exchange mechanisms.

ABSTRACT: Nitrate and nitrite transport across biological membranes is often facilitated by protein transporters that are members of the major facilitator superfamily. Paracoccus denitrificans contains an unusual arrangement whereby two of these transporters, NarK1 and NarK2, are fused into a single protein, NarK, which delivers nitrate to the respiratory nitrate reductase and transfers the product, nitrite, to the periplasm. Our complementation studies, using a mutant lacking the nitrate/proton symporter NasA from the assimilatory nitrate reductase pathway, support that NarK1 functions as a nitrate/proton symporter while NarK2 is a nitrate/nitrite antiporter. Through the same experimental system, we find that Escherichia coli NarK and NarU can complement deletions in both narK and nasA in P. denitr

SUBMITTER: Goddard AD 

PROVIDER: S-EPMC5217062 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature