Journal article
Evaluating the oligomeric state of SecYEG in preprotein translocase
The EMBO journal, Vol.19(16), pp.4393-4401
08/15/2000
DOI: 10.1093/emboj/19.16.4393
PMCID: PMC302025
PMID: 10944122
Abstract
SecA insertion and deinsertion through SecYEG drive preprotein translocation at the
Escherichia coli
inner membrane. We present three assessments of the theory that oligomers of SecYEG might form functional translocation sites. (i) Formaldehyde cross- linking of translocase reveals cross-links between SecY, SecE and SecG, but not higher order oligomers. (ii) Cross-linking of membranes containing unmodified SecE and hemagglutinin-tagged SecE (SecE
HA
) reveals cross-links between SecY and SecE and between SecY and SecE
HA
. However, anti-HA immunoprecipitates contain neither untagged SecE nor SecY cross-linked to SecE. (iii) Membranes containing similar amounts of SecE and SecE
HA
were saturated with translocation intermediate (I
29
) and detergent solubilized. Anti-HA immunoprecipitation of I
29
required SecYE
HA
G and SecA, yet untagged SecE was not present in this translocation complex. Likewise, anti-HA immunoprecipitates of membranes containing equal amounts of SecY and SecY
HA
were found to contain SecY
HA
but not SecY. Both immunoprecipitates contain more moles of I
29
than of the untagged subunit, again suggesting that translocation intermediates are not engaged with multiple copies of SecYEG. These studies suggest that the active form of preprotein translocase is monomeric SecYEG.
Details
- Title: Subtitle
- Evaluating the oligomeric state of SecYEG in preprotein translocase
- Creators
- Timothy L Yahr - Department of Biochemistry, Dartmouth Medical School, 7200 Vail Building, Hanover, NH 03755-3844, USAWilliam T Wickner - Department of Biochemistry, Dartmouth Medical School, 7200 Vail Building, Hanover, NH 03755-3844, USA
- Resource Type
- Journal article
- Publication Details
- The EMBO journal, Vol.19(16), pp.4393-4401
- DOI
- 10.1093/emboj/19.16.4393
- PMID
- 10944122
- PMCID
- PMC302025
- NLM abbreviation
- EMBO J
- ISSN
- 0261-4189
- eISSN
- 1460-2075
- Publisher
- Oxford University Press; Oxford, UK
- Language
- English
- Date published
- 08/15/2000
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984001216902771
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