Matrix-processing peptidase

This a-helix is amphipathic, containing patches of positively charged and hydrophobic amino acids, respectively, on opposite surfaces of the theoretical cylinder. The presequence is usually processed by the mitochondrial processing peptidase (MPP) and the mature protein is sorted to either the matrix, or to the inner membrane if it bears a hydrophobic stop-transfer sequence. Some mitochondrial proteins, mostly destined to the membranes, do not have cleavable N-terminal presequences but have internal targeting signals that are not well characterized (Pfanner and Geissler 2001). 

The mitochondrial processing peptidase is an essential zinc-dependent met-allopeptidase (Yaffe et al. 1985 Luciano and Geli 1996 Gakh et al. 2002 Nomura et al. 2006). It cleaves the N-terminal presequence from precursors to matrix-targeted proteins, and from precursors destined for the inner mem-... 

After translocation into the mitosome, the N-terminal presequences of mitosomal proteins are cleaved off, most likely by a peptidase that is homologous to the mitochondrial processing peptidase (MPP). The MPP is a matrix-localized metallopeptidase with a zinc binding motif His-X-X-Glu-His that is conserved in the putative mitosomal processing peptidase reported in G. intestinalis (Dolezal et al. 2005). 

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