Glutaredoxin-related protein [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 488966861   1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIFATMPDFKEFLRLRDASPAFAHAKEQGSVGIPACVKEDGEIFTDWEGF 80
Cdd:COG4545    2 KLILYGSELCPDCAPAKEELKELGIDYEFVDITESLANLKEFLKLRDTRAAFDDAKANGYIGIPCLVLEDGEITLDLEEL 81

                 ....*
gi 488966861  81 LKDQG 85
Cdd:COG4545   82 LDFFG 86

Glutaredoxin-related protein [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 488966861   1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIFATMPDFKEFLRLRDASPAFAHAKEQGSVGIPACVKEDGEIFTDWEGF 80
Cdd:COG4545    2 KLILYGSELCPDCAPAKEELKELGIDYEFVDITESLANLKEFLKLRDTRAAFDDAKANGYIGIPCLVLEDGEITLDLEEL 81

                 ....*
gi 488966861  81 LKDQG 85
Cdd:COG4545   82 LDFFG 86

NrdH-redoxin (NrdH) family; NrdH is a small monomeric protein with a conserved redox active CXXC motif within a TRX fold, characterized by a glutaredoxin (GRX)-like sequence and TRX-like activity profile. In vitro, it displays protein disulfide reductase activity that is dependent on TRX reductase, not glutathione (GSH). It is part of the NrdHIEF operon, where NrdEF codes for class Ib ribonucleotide reductase (RNR-Ib), an efficient enzyme at low oxygen levels. Under these conditions when GSH is mostly conjugated to spermidine, NrdH can still function and act as a hydrogen donor for RNR-Ib. It has been suggested that the NrdHEF system may be the oldest RNR reducing system, capable of functioning in a microaerophilic environment, where GSH was not yet available. NrdH from Corynebacterium ammoniagenes can form domain-swapped dimers, although it is unknown if this happens in vivo. Domain-swapped dimerization, which results in the blocking of the TRX reductase binding site, could be a mechanism for regulating the oxidation state of the protein.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 488966861   1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIfatmpdfkeflrlrDASPAFA--HAKEQGSVGIPACVKEDGEiftdWE 78
Cdd:cd02976    1 EVTVYTKPDCPYCKATKRFLDERGIPFEEVDV--------------DEDPEALeeLKKLNGYRSVPVVVIGDEH----LS 62

                 ....*.
gi 488966861  79 GFLKDQ 84
Cdd:cd02976   63 GFRPDK 68

Glutaredoxin-related protein [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 488966861   1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIFATMPDFKEFLRLRDASPAFAHAKEQGSVGIPACVKEDGEIFTDWEGF 80
Cdd:COG4545    2 KLILYGSELCPDCAPAKEELKELGIDYEFVDITESLANLKEFLKLRDTRAAFDDAKANGYIGIPCLVLEDGEITLDLEEL 81

                 ....*
gi 488966861  81 LKDQG 85
Cdd:COG4545   82 LDFFG 86

Glutaredoxin-like protein, YruB-family; This glutaredoxin-like protein family contains the conserved CxxC motif and includes the Clostridium pasteurianum protein YruB which has been cloned from a rubredoxin operon. Somewhat related to NrdH, it is unknown whether this protein actually interacts with glutathione/glutathione reducatase, or, like NrdH, some other reductant system.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 488966861    1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIFATMPDFKEFLrlrdaspafahaKEQGSVGIPACVKeDGEIFTdweGF 80
Cdd:TIGR02196   1 KVKVYTTPWCPPCVKAKEYLTSKGVAFEEIDVEKDAAAREELL------------KVYGQRGVPVIVI-GHKIVV---GF 64

                  ....
gi 488966861   81 LKDQ 84
Cdd:TIGR02196  65 DPEK 68

Arsenate Reductase (ArsC) family, Spx subfamily; Spx is a unique RNA polymerase (RNAP)-binding protein present in bacilli and some mollicutes. It inhibits transcription by binding to the C-terminal domain of the alpha subunit of RNAP, disrupting complex formation between RNAP and certain transcriptional activator proteins like ResD and ComA. In response to oxidative stress, Spx can also activate transcription, making it a general regulator that exerts both positive and negative control over transcription initiation. Spx has been shown to exert redox-sensitive transcriptional control over genes like trxA (TRX) and trxB (TRX reductase), genes that function in thiol homeostasis. This redox-sensitive activity is dependent on the presence of a CXXC motif, present in some members of the Spx subfamily, that acts as a thiol/disulfide switch. Spx has also been shown to repress genes in a sulfate-dependent manner independent of the presence of the CXXC motif.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 488966861   1 MLKVYGTKICPDCIACEASFKKYGIGYEFVNIFATMPDFKEFLRL 45
Cdd:cd03032    1 MIKLYTSPSCSSCRKAKQWLEEHQIPFEERNLFKQPLTKEELKEI 45