BMC Genomics 2005, 6:125 http://www.biomedcentral.com/1471-2164/6/125 rTS_ai rTS_kr rTS_xa* rTS_xc rTS_sa rTS_at* rTS_bm* rTS_sm* rTS_ss rTS_bc rTS_yp* rTS_um# rTS_cn# rTS_nc# rTS_mg rTS_gz rTS_an rTS_ps rTS_ppu* rTS_bf* rTS_rx rTS_ag# rTS_am# rTS_fr rTS_dr rTS_hs* rTS_pt# rTS_pp rTS_cf rTS_bt rTS_xl rTS_ci ---MS---IITAVDTFDIRFPTSLELDGSDAMNPDPDYSAAYLIIRTDAGDGHEGHGFVF CAD61030.1 ---MAGPERFTRFETLDVRFPTSRHLDGSDAMNPDPDYSAAYLVLGTDDPRSPEGHGFAF ZP_00227861.1 ------MSTIVALDTHDVRFPTSRELDGSDAMNPDPDYSAAYVVLRTDAADDLAGYGLVF NP_644487.1 ------MRTIIALETHDVRFPTSRELDGSDAMNPDPDYSAAYVVLRTDGAEDLAGYGLVF NP_639408.1 --MSPTAARITAVDTHDIRFPTSRELDGSDAMNPDPDYSAAYVVLRTDAADGIEGHGFSF NP_828458.1 ------MTKITDLRVFDLRFPTSQSLDGSDAMNPDPDYSAAYVILDTDEP-RLKGHGLTF NP_533476.1 ------MTKITDLRVFDLRFPTSQSLDGSDAMNPDPDYSAAYVILDTDDE-ALKGHGLTF NP_540624.1 ------MTRITDLRVFDLRFPTSASLDGSDAMNPDPDYSAAYVILDTDRP-GLAGHGLTF NP_437232.1 ------MTKITGLRTYDLRFPTSEGLDGSDAMNPDPDYSAAYVILETEG—-THEGHGLTF ZP_00337422.1 ------------MRVLDVRFPTSRQLDGSDAMNPDPDYSAAYVVLETDRD-GLEGHGLTF ZP_00213853.1 ------MTIITALRTEDVRFPTSLELDGSDAMNPDPDYSAAYVILDTDNP-ALSGHGLTF NP_405150.1 -MTKLSPLVVSSYSIHDVRFPTSLTGDGTDAMNKSCDYSAAYLILYTDGS—-LRGFGMTF EAK83237.1 ----MSGLKITEFSVHDIRFPTNVTGDGTDAMNKECDYSAAYIVVKTNSD—-LKGQGMTF EAL22592.1 --MSDQEITITGWTTRDVRFPTSLDKTGSDAMNAAGDYSAAYCILQTDSK—-YTGHGMTF XP_327350.1 --MAAQEITITGWKTRDVRFPTSLDKTGSDAMNAAGDYSSAYCILETDSE—-FSGHGMTF EAA55649.1 --MG--EITITGWKTRDVRFPTSLDGTGSDAMNAAGNYSSAYCILQTDSD—-YTGHGMTF EAA76898.1 ------MVKITGFITRDVRFPTSLDKTGSDAMNAAGDYSSAYCILYTDSP—-YSGHGMTF EAA58010.1 -----MTTTITRLSVRDIRFPTSRSLDGSDAMNAAPDYSATYVVLHTDAAQTLEGHGLTF ZP_00361027.1 -----MSIRITHLSVRDIRFPTSLSLDGSDAMNSAPDYSAAYVVLHTDAAA-LEGHGLTF NP_744975.1 ------MTTITRLSVRDIRFPTSRSLDGSDAMNAAPDYSAAYVTLETDSPQALTGHGLTF ZP_00281771.1 ----MSPLRITGVEALDVRFPTSRDLSGSDAMNPAPDYSAAYAILRT—-GEGLDGHGLTF ZP_00351773.1 -MGKDRCLNITTLQAKDIRWPTSLGAHGSDAMHTDPDYSCVYVTIAT—-AEGVTGYGMTF EAA04613.1 -MHNNK--DNSNIDVKDIRFPTSLLADGSDAMHTDPDYSCAYVTIKT—-KKGIEGYGLTF XP_394781 --MLHK---IVKLTVMDVRFPTSSEQHGSDAMHTDPDYSAAYVVIET—-ECGLKGFGLTF JGI_13714 -MLAIK---IINVSVRDVRFPTSLEQHGSDAMHTDPDYSVAYVVLETD-KAELKGYGLTF -MVRGR---ISRLSVRDVRFPTSLGGHGADAMHTDPDYSAAYVVIETDAEDGIKGCGITF NP_059982.1 -MVRGR---ISRLSVRDVRFPTSLGGHGSDAMHTDPDYSAAYVVIETDAEDGIKGCGITF chr17_1.249 -MVRGR---IFRLSVRDVRFPTSLGGHGSDAMHTDPDYSAAYVVIETDAEDGIKGCGITF CAH91126.1 -MVRGR---ICSLLVRDVRFPTSLGGHGSDAMHTDPDYSAAYVVLETDAEDGLKGYGITF chr7_14.29 -MVHGR---VSRLSVHDVRFPTSLGGHGSDAMHTDPDYSAAYVVLETDAEDGLKGYGITF -MITGK---ITCLHITDVRFPTSLDQHGSDAMHTDPDYSAAYVVIETDAADGLKGHGLTF AAH72148.1 MEVTGK---ITKIDVCDVRFPTSLEHHGSDAMHGEVDYSAAYVTMATD-ADDVIGCGLTF AK116577.1 SFeigquernec2e conservation within the extended N-terminal regions among all available rTS genes Sequence conservation within the extended N-terminal regions among all available rTS genes. The N-terminal section of all available rTS protein sequences were analyzed using Clustal X followed by boxshading using the BOXSHADE server [32]. The arrow indicates the start methionine in the short form of rTS proteins. Black boxed residues are identical, grey boxed residues are similar. The species name of each sequence is indicated by the last two letters in the sequence ID (ag, Anopheles gambiae; ai, Arthrobacter ilicis; am, Apis mellifera; an, Aspergillus nidulans; at, Agrobacterium tumefaciens; bc, Burkholderia cepacia; bf, Burkholderia fungorum; bm, Brucella melitensis; bt, Bos tauras; cf, Canis familiaris; ci, Ciona intestinalis; cn, Cryptococcus neo- formans; dr, Danio rerio; fr, Takifugu rubripes; gz, Gibberella zeae; hs, Homo sapien; kr, Kineococcus radiotolerans; mg, Magnaporthe gri- sea; nc, Neurospora crassa; pp, Pongo pygmaeus; ppu, Pseudomonas putida KT2440; ps, Polaromonas sp. JS666; pt, Pan troglodytes; rx, Rubrobacter xylanophilus; sa, Streptomyces avermitilis; sm, Sinorhizobium meliloti; ss, Silicibacter sp. TM1040; tr, Takifugu radiatus; um, Ustilago maydis; xa, Xanthomonas axonopodis; xc, Xanthomonas campestris; xl, Xenopus laevis; yp, Yersinia pestis). The accession numbers of the sequences are provide in the last column of the alignment. Sequences labeled with * are those annotated with a shorter N-terminus, while those labeled with # are the ones containing extra sequences at the N-terminus (see complete sequences in Additional file 1). to contain a mitochondrial signal. As shown in Table 1, all available programs predict a strong mitochondrial signal for rTSγ, but not for rTSβ, suggesting that the mitochon- drial signal is conferred by the extended N-terminal sequence. rTSγ protein exists and is associated with mitochondria in human cells We addressed the existence of the rTSγ isoform and its possible association with mitochondria experimentally. Initially, a cytosolic fraction and an organellar pellet Page 4 of 10 (page number not for citation purposes)