Biochemical and structural insights into bacterial organelle form and biogenesis.
Many heterotrophic bacteria have the ability to make polyhedral structures containing metabolic enzymes that are bounded by a unilamellar protein shell (metabolosomes or enterosomes). These bacterial organelles contain enzymes associated with a specific metabolic process (e.g. 1,2-propanediol or ethanolamine utilization). We show that the 21 gene regulon specifying the pdu organelle and propanediol utilization enzymes from Citrobacter freundii is fully functional when cloned in Escherichia coli, both producing metabolosomes and allowing propanediol utilization. Genetic manipulation of the level of specific shell proteins resulted in the formation of aberrantly shaped metabolosomes, providing evidence for their involvement as delimiting entities in the organelle. This is the first demonstration of complete recombinant metabolosome activity transferred in a single step and supports phylogenetic evidence that the pdu genes are readily horizontally transmissible. One of the predicted shell proteins (PduT) was found to have a novel Fe-S center formed between four protein subunits. The recombinant model will facilitate future experiments establishing the structure and assembly of these multiprotein assemblages and their fate when the specific metabolic function is no longer required.
Parsons
Joshua B
JB
Protein Science Group, Department of Biochemistry, University of Kent, Canterbury, Kent, UK.
Dinesh
Sriramulu D
SD
Deery
Evelyne
E
Leech
Helen K
HK
Brindley
Amanda A
AA
Heldt
Dana
D
Frank
Steffanie
S
Smales
C Mark
CM
Lünsdorf
Heinrich
H
Rambach
Alain
A
Gass
Mhairi H
MH
Bleloch
Andrew
A
McClean
Kirsty J
KJ
Munro
Andrew W
AW
Rigby
Stephen E J
SE
Warren
Martin J
MJ
Prentice
Michael B
MB
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001669:Biochemical Phenomena; D001671:Biochemistry; D003001:Cloning, Molecular; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D001678:Organelle Biogenesis; D015388:Organelles / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D011408:Propanediol Dehydratase / Q000378:metabolism; D019946:Propylene Glycol; D053719:Tandem Mass Spectrometry
D001426:Bacterial Proteins; D019946:Propylene Glycol; D011408:Propanediol Dehydratase