The TopicPages involved with the Localization of EcoProteins to Membranes are subdivided into
Inner Membrane Proteins (IMemProt), Outer Membrane Proteins (OMemProt), and Lipoproteins (LipoProt),
each with their own TopicPages. The IMemProt and OMemProt designations are based on
experimental 2DMS protein identifications that include lipoproteins, which are localized to either the OM or IM.
IMemProt and OMemProt include predictions for non-lipoprotein inner or outer membrane proteins.
Experimentally verified lipoproteins (LipoProt_Veri) are distinguished from probable lipoprotein predictions
supported by homology analysis (LipoProt_Prob), and predictions of likely
lipoproteins without homology support (LipoProt_Pred), as described on the LipoProteome TopicPage.
Inner Membrane Proteome------------
Outer Membrane Proteome------------
LipoProteome
In addition to serving as a SuperTopic Index for Membrane Protein TopicPages, this Membrane Proteome TopicPage
serves as a guide to the biology of
E. coli membrane proteins in general. As an initial focus, recent localizations based
on 2DMS (two dimensional gel electrophoresis of subfractions followed by spot identification
using mass spectrometry methods) are identified by tagged hyperlinks to Membrane Protein TopicPages.
If inner and outer membrane fractionation was not performed, the category tag "Mem_Loc_2DMS" is added to the link
and it links to this page. Other 2DMS studies may have further localized the membrane proteins and they are summarized
on the other Membrane Protein TopicPages.
A recent study by Lai et al. identified 28
E. coli proteins from rod and minicell membrane preparations.
They did not separate inner and outer membranes. The GenePages for these 28 proteins have links to this
TopicPage that are labeled "Mem_Loc_2DMS" for
"experimentally determined membrane localization based on 2DMS".
These proteins are usually localized to either the inner or the outer membrane fractions, and
these assignments, based on 2DMS data in other publications, or other types of localization
experiments, or bioinformatics predictions, are noted in the GenePages.
Lai EM, Nair U, Phadke ND, Maddock JR, Proteomic screening and identification of differentially distributed membrane proteins in Escherichia coli, Mol Microbiol (2004) 52:1029-44.9
Lai(2004) used minicell/rod-enrichment as a screen for asymmetrically localized membrane proteins,
and further showed polar OmpW and polar/septal YiaF. Lai(2004) washed with alkaline carbonate to reduce
cytoplasmic protein contamination. This may also have removed some membrane-associated proteins.
EcoInterGene
