TABLE 1 .

Functional categories of genes essential for R. palustris longevity

Functional group	No. of genes (n = 117)	Functions of selected longevity genes
Biosynthesis and metabolism	34	Nitrogenase cofactor biosynthesis protein (NifB), alkaline phosphatase, hydrogenase/expression formation proteins, acetyl-CoA hydrolase
Hypothetical or unknown functional category	43
DNA replication and repair	2	Smr protein/MutS2; Holliday junction resolvase-like protein
Cell wall/membrane biogenesis	2	Alanine racemase; UDP-N-acetylmuramoyl-l-alanyl-d-glutamate synthetase (MurD)
Signal transduction	3	Two-component sensor kinase (FixL), sensor signal transduction kinase of unknown function
Transcription	8	GTP-pyrophosphokinase (RelA), cold shock DNA-binding domain-containing protein (CspA)
Translation and posttranslational modification	10	tRNA uridine 5-carboxymethylaminomethyl modification protein (GidA), GTP-dependent nucleic acid-binding protein (EngD)
Transport	15	Twin-arginine translocation protein (TatB), high-affinity leucine-isoleucine-valine transport system periplasmic binding protein