Novel nitrite reductase domain structure suggests a chimeric denitrification repertoire in the phylum Chloroflexi

This study identifies a novel Nir domain architecture and expanded diversity in a rarely reported nitric oxide reductase variant (eNOR) in members of the bacterial phylum Chloroflexi. AbstractDenitrification plays a central role in the global nitrogen cycle, reducing and removing nitrogen from marine and terrestrial ecosystems. The flux of nitrogen species through this pathway has a widespread impact, affecting ecological carrying capacity, agriculture, and climate. Nitrite reductase (Nir) and nitric oxide reductase (NOR) are the two central enzymes in this pathway. Here we present a previously unreported Nir domain architecture in members of phylum Chloroflexi. Phylogenetic analyses of protein domains within Nir indicate that an ancestral horizontal transfer and fusion event produced this chimeric domain architecture. We also identify an expanded genomic diversity of a rarely reported NOR subtype, eNOR. Together, these results suggest a greater diversity of denitrification enzyme arrangements exist than have been previously reported.

Source: MicrobiologyOpen - January 13, 2022 Category: Microbiology Authors: Sarah L. Schwartz, Lily Momper, Luiz Thiberio Rangel, Cara Magnabosco, Jan P. Amend, Gregory P. Fournier Tags: ORIGINAL ARTICLE Source Type: research