Survey of large protein complexes in D. vulgaris reveals great structural diversity.
An unbiased survey has been made of the stable, most abundant multi-protein complexes in Desulfovibrio vulgaris Hildenborough (DvH) that are larger than Mr approximately 400 k. The quaternary structures for 8 of the 16 complexes purified during this work were determined by single-particle reconstruction of negatively stained specimens, a success rate approximately 10 times greater than that of previous "proteomic" screens. In addition, the subunit compositions and stoichiometries of the remaining complexes were determined by biochemical methods. Our data show that the structures of only two of these large complexes, out of the 13 in this set that have recognizable functions, can be modeled with confidence based on the structures of known homologs. These results indicate that there is significantly greater variability in the way that homologous prokaryotic macromolecular complexes are assembled than has generally been appreciated. As a consequence, we suggest that relying solely on previously determined quaternary structures for homologous proteins may not be sufficient to properly understand their role in another cell of interest.
Han
Bong-Gyoon
BG
Life Sciences, Genomics, Earth Sciences, and Physical Biosciences Divisions, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA.
Dong
Ming
M
Liu
Haichuan
H
Camp
Lauren
L
Geller
Jil
J
Singer
Mary
M
Hazen
Terry C
TC
Choi
Megan
M
Witkowska
H Ewa
HE
Ball
David A
DA
Typke
Dieter
D
Downing
Kenneth H
KH
Shatsky
Maxim
M
Brenner
Steven E
SE
Chandonia
John-Marc
JM
Biggin
Mark D
MD
Glaeser
Robert M
RM
D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D018360:Crystallography, X-Ray; D030562:Databases, Protein; D016969:Desulfovibrio vulgaris / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation
D001426:Bacterial Proteins; D046912:Multiprotein Complexes