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.
Polianskyte
Zydrune
Z
Research Program of Molecular Neurology, Institute of Biomedicine, University of Helsinki, FIN-00290 Helsinki, Finland.
Peitsaro
Nina
N
Dapkunas
Arvydas
A
Liobikas
Julius
J
Soliymani
Rabah
R
Lalowski
Maciej
M
Speer
Oliver
O
Seitsonen
Jani
J
Butcher
Sarah
S
Cereghetti
Grazia M
GM
Linder
Matts D
MD
Merckel
Michael
M
Thompson
James
J
Eriksson
Ove
O
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