Skip Navigation


Journal of Biochemistry Advance Access originally published online on March 3, 2008
Journal of Biochemistry 2008 143(6):747-758; doi:10.1093/jb/mvn033
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Data
Right arrow All Versions of this Article:
143/6/747    most recent
mvn033v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Nakai, T.
Right arrow Articles by Kamiya, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nakai, T.
Right arrow Articles by Kamiya, N.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2008 The Japanese Biochemical Society

Structural bases for the specific interactions between the E2 and E3 components of the Thermus thermophilus 2-oxo acid dehydrogenase complexes

Tadashi Nakai1,*, Seiki Kuramitsu1,2 and Nobuo Kamiya1,3

1RIKEN SPring-8 Center, Harima Institute, Sayo, Hyogo 679-5148, Japan; 2Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan; and 3Department of Chemistry, Graduate School of Science, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan

*To whom correspondence should be addressed. Tel: +1-206-616-4510, Fax: +1-206-685-7002, E-mail: nakaix{at}u.washington.edu

Received January 7, 2008; Accepted February 13, 2008


  Abstract

Pyruvate dehydrogenase (PDH), branched-chain 2-oxo acid dehydrogenase (BCDH) and 2-oxoglutarate dehydrogenase (OGDH) are multienzyme complexes that play crucial roles in several common metabolic pathways. These enzymes belong to a family of 2-oxo acid dehydrogenase complexes that contain multiple copies of three different components (E1, E2 and E3). For the Thermus thermophilus enzymes, depending on its substrate specificity (pyruvate, branched-chain 2-oxo acid or 2-oxoglutarate), each complex has distinctive E1 (E1p, E1b or E1o) and E2 (E2p, E2b or E2o) components and one of the two possible E3 components (E3b and E3o). (The suffixes, p, b and o identify their respective enzymes, PDH, BCDH and OGDH.) Our biochemical characterization demonstrates that only three specific E3•E2 complexes can form (E3b•E2p, E3b•E2b and E3o•E2o). X-ray analyses of complexes formed between the E3 components and the peripheral subunit-binding domains (PSBDs), derived from the corresponding E2-binding partners, reveal that E3b interacts with E2p and E2b in essentially the same manner as observed for Geobacillus stearothermophilus E3•E2p, whereas E3o interacts with E2o in a novel fashion. The buried intermolecular surfaces of the E3b•PSBDp/b and E3o•PSBDo complexes differ in size, shape and charge distribution and thus, these differences presumably confer the binding specificities for the complexes.

Key Words: {alpha}-ketoacid dehydrogenase, glycine cleavage system, 2-oxo acid dehydrogenase, protein-protein interaction complex, Thermus thermophilus

Abbreviations: ASA, accessible surface area; BCDH, branched-chain 2-oxo acid dehydrogenase; E3BD, E3-binding domain; GCS, glycine cleavage system; Gst, Geobacillus stearothermophilus; OGDH, 2-oxoglutarate dehydrogenase; PDH, Pyruvate dehydrogenase; PSBD, peripheral subunit binding domain; Tth, Thermus thermophilus; rms, root-mean-square


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.