Table 1. Mutant strains.

Mutant strain	Disrupted gene	Assigned function	Assigned location	Reference	Color code
ΔfutA1	slr1295	Fe(III)-binding protein	Cytoplasmic and thylakoid membranes	30–32	Blue
ΔfutA2	slr0513	Fe(III)-binding protein	Periplasm	27, 28	Blue
ΔfutA1ΔfutA2	slr0513, slr1295			27	Blue
ΔfutC	sll1878	Fe(III) transport ATP-binding protein	Peripheral plasma membrane	27	Blue
ΔARTO	slr2082, slr2083	Cytochrome c oxidase homolog	Integral plasma membrane	33, 34	Orange
ΔfeoB	slr1392	Fe(II) transporter	Plasma membrane	27	Green

The table summarizes all of the mutant strains used in this study, the disrupted genes, assigned function and location based on previous work. For clarity, each transporter and mutant was assigned a color code that is used throughout this work.