71     Tc00.1047053503613.60 Q4JH30 3537396 414 47854 5.71   T. vivax Tviv426a04.q1k_3 —   414 47727 5.75   L. braziliensis Tipifarnib LbrM19_V2.0110 A4H9T7 5414648 443 51256 5.51   L. infantum LinJ11.0210

A4HUT3 5067199 412 47390 5.52   L. major LmjF11.0210 Q4QH59 5649763 443 50994 5.38   L. tarentolae r1596.contig1511-1-4543-5877 —   443 51075 5.40   L. amazonensis — Q7Z031   443 51175 5.32 [35] Group 3 (cytosolic pyrophosphatases)   —           T. brucei Tb927.3.2840 Q57ZM8 3656220 261 28676 5.66   T. congolense congo1253h06.p1k_11     262 29016 5.67   T. cruzi Tc00.1047053508153.820 Q4E611 3555184 276 31146 5.76     Tc00.1047053508181.140 Q4DR95 3548870 271 30554 6.12   T. vivax tviv222a06.p1k_8 —   263 26220 5.15   L. braziliensis LbrM03_V2.0820 A4H3Q3 5412574 269 29744 5.90   L. infantum LinJ03.0510 A4HRX7 5066310 226 25108 5.15   L. major LmjF03.0910 Q9N640 809741 226 24973 5.41   L. tarentolae r1596.contig6751-4-7549-6743 —   263 28971 5.83   Group 1 contains the exopolyphosphatases, and group 2 consists of the acidocalcisomal inorganic pyrophosphatases. For both groups, the activities

of representative members have been experimentally determined. Group 3 represents a homogeneous group of predicted, putatively LXH254 cytosolic inorganic pyrophosphatases for which no experimental data are available so far. Designations are by gene name (TriTrypDB), by the TrEMBL database nomenclature and by gene identification number (where available). Total amino acid numbers and calculated molecular mass and pI values are also given. Analysis of the kinetoplastid genomes for the presence of additional poly- or pyrophosphatases resulted in the identification of two additional groups

(Figure 2). Group 2 represents the kinetoplastid-specific acidocalcisomal pyrophosphatases, Nintedanib one of which [GeneDB: Tb11.02.4930] has been experimentally characterized [12, 13]. Their lengths vary from 414 to 443 amino acids, with isoelectric points between 5.3 and 5.8. They are all characterized by an inorganic pyrophosphatase domain [InterPro: IPR008162] which, in Tb11.02.4930 extends from amino acids 225 to 404. Finally, group 3 represents yet uncharacterized, putatively cytosolic pyrophosphatases, with lengths from 260 to 320 amino acids and pIs varying from 5.2 to 6.3. Their sequences also contain the inorganic pyrophosphatase domain, extending from about amino acids 67 to 247. Interestingly, no recognizable genes coding for endopolyphosphatases were detected in any of the kinetoplastid genomes. Expression and subcellular localization of TbrPPX1 RT-PCR and Northern blotting demonstrated that the TbrPPX1 gene is expressed at similar levels both in bloodstream and in procyclic forms. The major transcripts in both stages carry a very short 5′-untranslated region of only 2 nucleotides length (data not shown).