TRX family; composed of two groups: Group I, which includes proteins that exclusively encode a TRX domain; and Group II, which are composed of fusion proteins of TRX and additional domains. Group I TRX is a small ancient protein that alter the redox state of target proteins via the reversible oxidation of an active site dithiol, present in a CXXC motif, partially exposed at the protein's surface. TRX reduces protein disulfide bonds, resulting in a disulfide bond at its active site. Oxidized TRX is converted to the active form by TRX reductase, using reducing equivalents derived from either NADPH or ferredoxins. By altering their redox state, TRX regulates the functions of at least 30 target proteins, some of which are enzymes and transcription factors. It also plays an important role in the defense against oxidative stress by directly reducing hydrogen peroxide and certain radicals, and by serving as a reductant for peroxiredoxins. At least two major types of functional TRXs have been reported in most organisms; in eukaryotes, they are located in the cytoplasm and the mitochondria. Higher plants contain more types (at least 20 TRX genes have been detected in the genome of Arabidopsis thaliana), two of which (types f amd m) are located in the same compartment, the chloroplast. Also included in the alignment are TRX-like domains which show sequence homology to TRX but do not contain the redox active CXXC motif. Group II proteins, in addition to either a redox active TRX or a TRX-like domain, also contain additional domains, which may or may not possess homology to known proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 516363455   8 EEIITFTNEQPLTFLYFSHPACNVCHSVFPKVENiLMNDFPEIAFGKINTEEVPECAGHFSIFTVPSMILFAEGKEVMRQ 87
Cdd:cd02947    1 EEFEELIKSAKPVVVDFWAPWCGPCKAIAPVLEE-LAEEYPKVKFVKVDVDENPELAEEYGVRSIPTFLFFKNGKEVDRV 79

                         90
                 ....*....|....
gi 516363455  88 ARFVVLDDLKAQIN 101
Cdd:cd02947   80 VGADPKEELEEFLE 93

thioredoxin 2; Provisional

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 516363455  24 FSHPACNVCHSVFPKVENILMNDFPEIAFGKINTEEVPECAGHFSIFTVPSMILFAEGKEV 84
Cdd:PRK10996  59 FWAPWCGPCRNFAPIFEDVAAERSGKVRFVKVNTEAERELSARFRIRSIPTIMIFKNGQVV 119

TRX family; composed of two groups: Group I, which includes proteins that exclusively encode a TRX domain; and Group II, which are composed of fusion proteins of TRX and additional domains. Group I TRX is a small ancient protein that alter the redox state of target proteins via the reversible oxidation of an active site dithiol, present in a CXXC motif, partially exposed at the protein's surface. TRX reduces protein disulfide bonds, resulting in a disulfide bond at its active site. Oxidized TRX is converted to the active form by TRX reductase, using reducing equivalents derived from either NADPH or ferredoxins. By altering their redox state, TRX regulates the functions of at least 30 target proteins, some of which are enzymes and transcription factors. It also plays an important role in the defense against oxidative stress by directly reducing hydrogen peroxide and certain radicals, and by serving as a reductant for peroxiredoxins. At least two major types of functional TRXs have been reported in most organisms; in eukaryotes, they are located in the cytoplasm and the mitochondria. Higher plants contain more types (at least 20 TRX genes have been detected in the genome of Arabidopsis thaliana), two of which (types f amd m) are located in the same compartment, the chloroplast. Also included in the alignment are TRX-like domains which show sequence homology to TRX but do not contain the redox active CXXC motif. Group II proteins, in addition to either a redox active TRX or a TRX-like domain, also contain additional domains, which may or may not possess homology to known proteins.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 516363455   8 EEIITFTNEQPLTFLYFSHPACNVCHSVFPKVENiLMNDFPEIAFGKINTEEVPECAGHFSIFTVPSMILFAEGKEVMRQ 87
Cdd:cd02947    1 EEFEELIKSAKPVVVDFWAPWCGPCKAIAPVLEE-LAEEYPKVKFVKVDVDENPELAEEYGVRSIPTFLFFKNGKEVDRV 79

                         90
                 ....*....|....
gi 516363455  88 ARFVVLDDLKAQIN 101
Cdd:cd02947   80 VGADPKEELEEFLE 93

TRX domain, PICOT (for PKC-interacting cousin of TRX) subfamily; PICOT is a protein that interacts with protein kinase C (PKC) theta, a calcium independent PKC isoform selectively expressed in skeletal muscle and T lymphocytes. PICOT contains an N-terminal TRX-like domain, which does not contain the catalytic CXXC motif, followed by one to three glutaredoxin domains. The TRX-like domain is required for interaction with PKC theta. PICOT inhibits the activation of c-Jun N-terminal kinase and the transcription factors, AP-1 and NF-kB, induced by PKC theta or T-cell activating stimuli.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 516363455   7 LEEIITfTNEQPLTFLYFSHPACNVCHSVFPKVENILMNDFPEIAFGKINTEEVPECAGHFSIFTVPSMILFAEGKEVMR 86
Cdd:cd02984    5 FEELLK-SDASKLLVLHFWAPWAEPCKQMNQVFEELAKEAFPSVLFLSIEAEELPEISEKFEITAVPTFVFFRNGTIVDR 83

TMX2 family; composed of proteins similar to human TMX2, a 372-amino acid TRX-related transmembrane protein, identified and characterized through the cloning of its cDNA from a human fetal library. It contains a TRX domain but the redox active CXXC motif is replaced with SXXC. Sequence analysis predicts that TMX2 may be a Type I membrane protein, with its C-terminal half protruding on the luminal side of the endoplasmic reticulum (ER). In addition to the TRX domain, transmembrane region and ER-retention signal, TMX2 also contains a Myb DNA-binding domain repeat signature and a dileucine motif in the tail.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 516363455   7 LEEIITFTNEQPL--TFLYFSHPACNVCHSVFPKVENILMNdfPEIAFGKINTEEVPECAGHFSIFT------VPSMILF 78
Cdd:cd02962   38 LEEELERDKRVTWlvEFFTTWSPECVNFAPVFAELSLKYNN--NNLKFGKIDIGRFPNVAEKFRVSTsplskqLPTIILF 115

                 ....*...
gi 516363455  79 AEGKEVMR 86
Cdd:cd02962  116 QGGKEVAR 123

disulphide isomerase; Provisional

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 516363455  13 FTNEQPLTFLYFSHPACNVCHSVFP---KVENILMNDFPEIAFGKINTEEVPECAGHFSIFTVPSMILFAEGKEV 84
Cdd:PTZ00102  45 FITENEIVLVKFYAPWCGHCKRLAPeykKAAKMLKEKKSEIVLASVDATEEMELAQEFGVRGYPTIKFFNKGNPV 119