Table 1

Fraction of singletons (Q) for various subsets of protein-encoding E. coli genes

Source
Protein subset
Number of proteins
Number of singletons
Q

SwissProt
Monomers
137
87
0.6350

Homo-oligomers + monomers
596
333
0.5587

Hetero-oligomers
407
228
0.5602

Mid-to-large complexes (homotrimer and above)
334
197
0.5898

1 external interaction
641
342
0.5335

>1 external interaction
125
75
0.5000
Arifuzzaman et al. 2006 [9]
1 external interaction
371
193
0.5202

>1 external interaction
1,916
1,049
0.5475
Ragan 2001 [11]
LGT due to atypical nucleotide composition
568
339
0.5968
Beiko et al. 2005 [13]
LGT by Bayesian phylogenetic analysis
987
607
0.6150
PEC database
Essential genes
233
173
0.7425

E. coli average
4,308
2,382
0.5529

Wellner et al. Genome Biology 2007 8:R156   doi:10.1186/gb-2007-8-8-r156