Table 5.

Major regulatory hubs from the core genome of an outlier and classical strains.

Regulatory hub	Degree	Protein	Function
Outliers
gltB	239	Glutamate synthase	Provides glutamate for the glutamine synthetase reaction, absent in animals
PA1400	221	Pyruvate carboxylase	Irreversible carboxylation of pyruvate to form oxaloacetate (OAA)
polA	171	DNA polymerase I	Prokaryotic DNA replication
gacS	159	Histidine kinase	Play a role in signal transduction across the cellular membrane.
guaA	146	GMP synthase	Converts xanthosine monophosphate to guanosine monophosphate in the de novo synthesis of purine nucleotides,
Classical
gltB	127	Glutamate synthase	Provides glutamate for the glutamine synthetase reaction, absent in animals
dnaK	67	Chaperone protein	DnaK is also involved in chromosomal DNA replication, possibly through an analogous interaction with the DnaA
guaB	57	Inosine 5′-monophosphate dehydrogenase	Purine biosynthetic enzyme; catalyzes the nicotinamide adenine dinucleotide (NAD+)-dependent oxidation of inosine monophosphate (IMP) to xanthosine monophosphate (XMP)
hemE	57	Uroporphyrin decarboxylase	Catalyzes the decarboxylation of four acetate groups of uroporphyrinogen-III to yield coproporphyrinogen-III
rpoA	55	DNA-directed RNA polymerase	Essential for life; significant role in transcription

Hubs with their degree of association, the protein encoded and the function performed by these proteins. gltB was the major regulator in both the groups and four group specific regulatory hubs.