LACTB is a filament-forming protein localized in mitochondria.
LACTB is a mammalian active-site serine protein that has evolved from a bacterial penicillin-binding protein. Penicillin-binding proteins are involved in the metabolism of peptidoglycan, the major bacterial cell wall constituent, implying that LACTB has been endowed with novel biochemical properties during eukaryote evolution. Here we demonstrate that LACTB is localized in the mitochondrial intermembrane space, where it is polymerized into stable filaments with a length extending more than a hundred nanometers. We infer that LACTB, through polymerization, promotes intramitochondrial membrane organization and micro-compartmentalization. These findings have implications for our understanding of mitochondrial evolution and function.
Research Program of Molecular Neurology, Institute of Biomedicine, University of Helsinki, FIN-00290 Helsinki, Finland.
Zydrune
Z
Polianskyte
Nina
N
Peitsaro
Arvydas
A
Dapkunas
Julius
J
Liobikas
Rabah
R
Soliymani
Maciej
M
Lalowski
Oliver
O
Speer
Jani
J
Seitsonen
Sarah
S
Butcher
Grazia M
GM
Cereghetti
Matts D
MD
Linder
Michael
M
Merckel
James
J
Thompson
Ove
O
Eriksson
D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D008297:Male; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046915:Penicillin-Binding Proteins / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011108:Polymers / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism*
D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D046915:Penicillin-Binding Proteins; D011108:Polymers; C486706:LACTB protein, human; D001618:beta-Lactamases