Comparative genomics of transport proteins in developmental bacteria: Myxococcus xanthus and Streptomyces coelicolor

Table 2 Counts of Sco transport proteins according to substrate type

Substrate		No. of proteins of indicated type acting on substrate type
		Channels/Pores	Primary Carriers	Secondary Carriers	Group translocators	Transmembrane electron flow carriers	Auxiliary proteins	(Putative) Poorly characterized	Total no. of systems
I. Inorganic Molecules
A.	Nonselective	5		1					6
B.	Cations	9	33	32				15	89
C.	Anions		6	15					21
D.	Electrons		29	2		9			40
II. Carbon sources
A.	Sugars & polyols	2	83	9	2				96
B.	Monocarboxylates		11	15					26
C.	Di- & tricarboxylates			7					7
D.	Organoanions (noncarboxylic)		2	6					8
E.	Aromatic Compounds			8					8
III. Amino acids & their derivatives
A.	Amino acids & conjugates	1	16	39					56
B.	Amines, amides, polyamines, & organocations	1	5	7	2				15
C.	Peptides		20	1					21
IV. Vitamins, cofactors & cofactor precursors
A.	Vitamins & vitamin or cofactor precursors		5	3	1				9
B.	Enzyme & redox cofactors								0
C.	Siderophores; siderophore-Fe complexes		21	8					29
V. Drugs, dyes, sterols & toxins
A.	Multiple drugs		20	36					56
B.	Specific drugs		4	58					62
C.	Pigments		7	1					8
D.	Other hydrophobic substances		6						6
VI. Macromolecules
A.	Carbohydrates	1	16				1		18
B.	Proteins	1	10				3	3	17
C.	Lipids		14	7	1				22
VII. Nucleic acids
A.	Nucleic acids		10	8	1			2	21
VIII. Unknown
A.	Unknown		3	14					17
Total		20	321	277	7	9	4	20	658

Substrate categories include: (I) inorganic molecules; (II) carbon sources; (III) amino acids & their derivatives; (IV) vitamins, cofactors & cofactor precursors; (V) drugs, dyes, sterols & toxins; (VI) macromolecules; (VII) nucleic acids; and (VIII) unknown.

ISSN: 1471-2180