Table 4. Putative mitosomal proteins classified by predicted function: various metabolic processes, lipid metabolism.
Accession number | Annotation | Identification | Localization | Structure | |||||||
MASCOT | Coverage | MiD | SignalP | Target P | Psort II | Exp Ver. | MEMSAT3 | SGP | TMHMM | ||
score | peptides | % mito | TM No. | TM No. | |||||||
Various metabolic processes | |||||||||||
GL50803_7203 | Guanylate kinase | * | * | * | N | M | 65% | O | 0 | # | 0 |
GL50803_3287 | Acetyl-CoA acetyltransferase | * | * | * | N | M | 22% | O | 0 | # | 0 |
GL50803_8163 | Manganese-dependent inorganic pyrophosphatase, putative | 25 | 1 | Y | N | O | 22% | 0 | # | 0 | |
GL50803_6497 | Metal-dependent hydrolase | 30 | 1 | Y | N | O | 13% | 1 | 0 | ||
GL50803_10311 | Ornithine carbamoyltransferase | 665 | 8 | Y | N | O | 9% | 1 | 0 | ||
GL50803_14993 | Pyrophosphate-fructose 6-phosphate 1-phosphotransferase alpha subunit | 56 | 1 | Y | N | M | 35% | 1 | 0 | ||
GL50803_15380 | CDC8 Thymidylate kinase | * | * | * | N | O | 35% | O | 0 | # | 0 |
Lipid metabolism | |||||||||||
GL50803_9062 | Long chain fatty acid CoA ligase 5 | 279 | 3 | Y | N | O | 22% | ** | 0 | # | 0 |
GL50803_21118 | Long chain fatty acid CoA ligase 5 | 25 | 1 | Y | N | O | 26% | 0 | # | 0 | |
GL50803_113892 | Long chain fatty acid CoA ligase, putative | 224 | 4 | Y | N | O | 26% | 0 | # | 0 | |
GL50803_7259 | CDP-diacylglycerol-glycerol-3-phosphate 3-phosphatidyltransferase | 43 | 1 | N | N | M | 22% | 6 | 2 |
Mascot score, Mascot total ion score for the identified protein. Coverage, number of unique peptides per identified protein. MiD, mitosomal distribution. Proteins are marked “Y” if their distributions in fractions #3 and #4 of the Optiprep gradient (measured by the iTRAQ ratio) were within the range between Cpn10 and IscU and the window that extended in both directions by half of the distance between these markers. Proteins with ratios outside of this range are indicated with “N”. TargetP and PsortII were used to predict the subcellular location of Giardia proteins. S, secretory; N, non-secretory; M, mitochondrial; O, other. Exp. ver., experimental verification of protein localization using the pONDRA expression vector. The recombinant tagged proteins were localized by fluorescence microscopy. M, mitosome; ER, endoplasmic reticulum; O, other; ? inconclusive. MEMSAT3 and TMHMM were used to predict transmembrane domains. SGP, predicted soluble proteins are marked with number sign (#). Asterisk (*) is used where no data were available. (**) transformed Giardia did not express the recombinant tagged protein.