Table 2.

Genes having at least two links with genes related to nitrogen fixation in S.meliloti

Gene	No. of links to core	Function of protein
cysH	5	Probable thioredoxin dependent padops reductase 3′-phosphoadenylylsulfate sulfotransferase cysteine biosynthesis protein
cysG	4	Probable siroheme synthase protein
cysQ	4	Putative transmembrane protein
SMc02124	4	Putative nitrite reductase protein
cobA	3	Probable uroporphyrin-III C-methyltransferase protein
fixG	3	Iron sulfur membrane protein
fixI1	3	Copper transport ATPase
cysD	2	Putative sulfate adenylate transferase subunit 2 cysteine biosynthesis protein
dcp	2	Probable peptidyl-dipeptidase A protein
etf	2	Probable electron transfer flavoprotein-ubiquinone oxidoreductase
fixI2	2	E1–E2 type cation ATPase
fixN1	2	Heme b/copper cytochrome c oxidase subunit
fixO2	2	cytochrome c oxidase
fixP1	2	Di-heme cytochrome c
glcF	2	Probable glycolate oxidase iron-sulfur subunit protein
ispB	2	Putative octaprenyl-diphosphate synthase protein
ivdH	2	Putative isovaleryl-CoA dehydrogenase protein
pfs	2	Putative MTA/SAH nucleosidase P46 includes: 5′-methylthioadenosine nucleosidase and S-adenosylhomocysteine nucleosidase protein
rpsJ	2	Probable 30S ribosomal protein S10
SMa1207	2	FixK-like regulatory protein
SMa2359	2	Conserved hypothetical protein
SMb20753	2	Putative acyl-CoA dehydrogenase protein
SMb21225	2	Putative inositol monophosphatase, possibly involved in PAPS metabolism protein
SMb21232	2	Putative nucleotide sugar epimerase dehydratase protein
SMc00977	2	Putative acyl-COA dehydrogenase protein
SMc01153	2	Probable enoyl COA hydratase protein
SMc02123	2	Conserved hypothetical protein
thiF	2	Putative Thiamine biosynthesis transmembrane protein
typA	2	Probable GTP-binding protein
ubiE	2	Probable ubiquinone/menaquinone biosíntesis methyltransferase protein