Imported mitochondrial proteins cytochrome b2 and cytochrome c1 are processed in two steps.

AUTOR(ES)

Gasser, S M

RESUMO

Cytochrome b2 of yeast is located in the space between the inner and outer mitochondrial membranes whereas cytochrome c1 is bound to the outer face of the mitochondrial inner membrane. Both proteins are made outside the mitochondria as larger precursors that are processed to their mature forms in two steps. In the first step, at least a segment of the precursor polypeptide chain penetrates into the mitochondrial matrix and is cleaved to an intermediate form by a matrix-localized soluble protease. This step requires an electrochemical gradient across the mitochondrial inner membrane. In the second step, the intermediate form is converted to the mature form. For cytochrome c1, this second step requires heme. Import of these two cytochromes thus involves a "detour" across the inner membrane.

Documentos Relacionados

• Mitochondrial cytochrome c1 is a collapsed di-heme cytochrome
• Transport of proteins to the mitochondrial intermembrane space: the 'matrix-targeting' and the 'sorting' domains in the cytochrome c1 presequence.
• There Are Two Different Species B Adenovirus Receptors: sBAR, Common to Species B1 and B2 Adenoviruses, and sB2AR, Exclusively Used by Species B2 Adenoviruses
• Exon shuffling and the origin of the mitochondrial targeting function in plant cytochrome c1 precursor.
• From one gene to two proteins: the biogenesis of cytochromes b and c1 in Bradyrhizobium japonicum.