Table I. SCL terms of membrane proteins in E. coli.

Location	Proteina	STEP	PSORT
Inner membrane (IM)	Peripheral IM (PIM)	Peripheral inner membrane protein facing the cytoplasm
		Peripheral inner membrane protein facing the periplasm
	IM	Integral inner membrane	Cytoplasmic membrane
		Inner membrane lipoprotein
Periplasm	Periplasmic	Periplasmic	Periplasm
Outer membrane (OM)	Peripheral OM (POM)	Peripheral outer membrane protein facing the periplasm
		Peripheral outer membrane protein facing the extracellular space
	OM	Outer membrane β-barrel protein	Outer membrane
		Outer membrane lipoprotein

^a Terms used in this study.