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The AAA(+) motor complex of subunits CobS and CobT of cobaltochelatase visualized by single particle electron microscopy.

Lundqvist, Joakim LU ; Elmlund, Dominika; Heldt, Dana; Deery, Evelyne; Söderberg, Christopher LU ; Hansson, Mats LU ; Warren, Martin and Al-Karadaghi, Salam LU (2009) In Journal of Structural Biology1991-01-01+01:00 167. p.227-234
Abstract
Cobalamins belong to the tetrapyrrole family of prosthetic groups(.) The presence of a metal ion is a key feature of these compounds. In the oxygen-dependent (aerobic) cobalamin biosynthetic pathway, cobalt is inserted into a ring-contracted tetrapyrrole called hydrogenobyrinic acid a,c-diamide (HBAD) by a cobaltochelatase that is constituted by 3 subunits, CobN, CobS and CobT, with molecular masses of 137, 37 and 71 kDa, respectively. Based on the similarities with magnesium chelatase, cobaltochelatase has been suggested to belong to the AAA(+) superfamily of proteins. In this paper we present the cloning of the Brucella melitensis cobN, cobS and cobT, the purification of the encoded protein products, and a single-particle reconstruction... (More)
Cobalamins belong to the tetrapyrrole family of prosthetic groups(.) The presence of a metal ion is a key feature of these compounds. In the oxygen-dependent (aerobic) cobalamin biosynthetic pathway, cobalt is inserted into a ring-contracted tetrapyrrole called hydrogenobyrinic acid a,c-diamide (HBAD) by a cobaltochelatase that is constituted by 3 subunits, CobN, CobS and CobT, with molecular masses of 137, 37 and 71 kDa, respectively. Based on the similarities with magnesium chelatase, cobaltochelatase has been suggested to belong to the AAA(+) superfamily of proteins. In this paper we present the cloning of the Brucella melitensis cobN, cobS and cobT, the purification of the encoded protein products, and a single-particle reconstruction of the macromolecular assembly formed between CobS and CobT from negatively stained electron microscopy images of the complex. The results show for the first time that subunits CobS and CobT form a chaperone-like complex, characteristic for the AAA(+) class of proteins. The molecules are arranged in a two-tiered ring structure with the 6 subunits in each ring organized as a trimer of dimers. The similarity between this structure and that of magnesium chelatase, as well as analysis of the amino acid sequences confirms the suggested evolutionary relationship between the two enzymes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Structural Biology1991-01-01+01:00
volume
167
pages
227 - 234
publisher
Elsevier
external identifiers
  • wos:000268775700006
  • pmid:19545636
  • scopus:67650753212
ISSN
1095-8657
DOI
10.1016/j.jsb.2009.06.013
language
English
LU publication?
yes
id
c89636fd-68ce-4803-bd0a-04512165f28b (old id 1434000)
date added to LUP
2009-07-03 09:09:11
date last changed
2017-12-17 03:37:52
@article{c89636fd-68ce-4803-bd0a-04512165f28b,
  abstract     = {Cobalamins belong to the tetrapyrrole family of prosthetic groups(.) The presence of a metal ion is a key feature of these compounds. In the oxygen-dependent (aerobic) cobalamin biosynthetic pathway, cobalt is inserted into a ring-contracted tetrapyrrole called hydrogenobyrinic acid a,c-diamide (HBAD) by a cobaltochelatase that is constituted by 3 subunits, CobN, CobS and CobT, with molecular masses of 137, 37 and 71 kDa, respectively. Based on the similarities with magnesium chelatase, cobaltochelatase has been suggested to belong to the AAA(+) superfamily of proteins. In this paper we present the cloning of the Brucella melitensis cobN, cobS and cobT, the purification of the encoded protein products, and a single-particle reconstruction of the macromolecular assembly formed between CobS and CobT from negatively stained electron microscopy images of the complex. The results show for the first time that subunits CobS and CobT form a chaperone-like complex, characteristic for the AAA(+) class of proteins. The molecules are arranged in a two-tiered ring structure with the 6 subunits in each ring organized as a trimer of dimers. The similarity between this structure and that of magnesium chelatase, as well as analysis of the amino acid sequences confirms the suggested evolutionary relationship between the two enzymes.},
  author       = {Lundqvist, Joakim and Elmlund, Dominika and Heldt, Dana and Deery, Evelyne and Söderberg, Christopher and Hansson, Mats and Warren, Martin and Al-Karadaghi, Salam},
  issn         = {1095-8657},
  language     = {eng},
  pages        = {227--234},
  publisher    = {Elsevier},
  series       = {Journal of Structural Biology1991-01-01+01:00},
  title        = {The AAA(+) motor complex of subunits CobS and CobT of cobaltochelatase visualized by single particle electron microscopy.},
  url          = {http://dx.doi.org/10.1016/j.jsb.2009.06.013},
  volume       = {167},
  year         = {2009},
}