Table 6.

Cluster of Orthologous Groups (COG) functional classes. Abbreviations for Fig. 8

Functional class	Class description
A	RNA processing and modification
B	Chromatin structure and dynamics
C	Energy production and conversion
D	Cell cycle control /cell division / chromosome partitioning
E	Amino acid transport and metabolism
F	Nucleotide transport and metabolism
G	Carbohydrate transport and metabolism
H	Coenzyme transport and metabolism
I	Lipid transport and metabolism
J	Translation / ribosomal structure and biogenesis
K	Transcription
L	Replication / recombination, and repair
M	Cell wall/membrane/envelope biogenesis
N	Cell motility
O	Posttranslational modification / protein turnover/ chaperones
P	Inorganic ion transport and metabolism
Q	Secondary metabolites biosynthesis, transport, and catabolism
R	General function prediction only
S	Function unknown
T	Signal transduction mechanisms
U	Intracellular trafficking / secretion, and vesicular transport
V	Defense mechanisms
W	Extracellular structures
Y	Nuclear structure
Z	Cytoskeleton