phosphoacceptor receiver (REC) domain of response regulators (RRs) and pseudo response regulators (PRRs); Two-component systems (TCSs) involving a sensor and a response regulator are used by bacteria to adapt to changing environments. Processes regulated by two-component systems in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Response regulators (RRs) share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. Response regulators regulate transcription, post-transcription or post-translation, or have functions such as methylesterases, adenylate or diguanylate cyclase, c-di-GMP-specific phosphodiesterases, histidine kinases, serine/threonine protein kinases, and protein phosphatases, depending on their output domains. The function of some output domains are still unknown. TCSs are found in all three domains of life - bacteria, archaea, and eukaryotes, however, the presence and abundance of particular RRs vary between the lineages. Archaea encode very few RRs with DNA-binding output domains; most are stand-alone REC domains. Among eukaryotes, TCSs are found primarily in protozoa, fungi, algae, and green plants. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  14 VVLVEDNEFLLEVMIGHLECYGAVCKAfgtADGASSYLDGVEKPPF--LVVTDHLLPGTLQGADLANQLAARWPDLSIIV 91
Cdd:cd18161     1 VLVVEDDPDVRRLTAEVLEDLGYTVLE---AASGDEALDLLESGPDidLLVTDVIMPGGMNGSQLAEEARRRRPDLKVLL 77

                          90
                  ....*....|...
gi 2445727555  92 ASGYLDRSQLPPR 104
Cdd:cd18161    78 TSGYAENAIEGGD 90

phosphoacceptor receiver (REC) domain of hybrid sensor histidine kinase/response regulators similar to Pseudomonas savastanoi blue-light-activated histidine kinase; Typically, two-component regulatory systems (TCSs) consist of a sensor (histidine kinase) that responds to specific input(s) by modifying the output of a cognate response regulator (RR). TCSs allow organisms to sense and respond to changes in environmental conditions. Hybrid sensor histidine kinase (HK)/response regulators contain all the elements of a classical TCS in a single polypeptide chain. Pseudomonas savastanoi blue-light-activated histidine kinase is a photosensitive HK and RR that is involved in increased bacterial virulence upon exposure to light. RRs share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  14 VVLVEDNEFLLEVMIGHLECYGAVCKAfgtADGASSYLDGVEKPPF--LVVTDHLLPGTLQGADLANQLAARWPDLSIIV 91
Cdd:cd18161     1 VLVVEDDPDVRRLTAEVLEDLGYTVLE---AASGDEALDLLESGPDidLLVTDVIMPGGMNGSQLAEEARRRRPDLKVLL 77

                          90
                  ....*....|...
gi 2445727555  92 ASGYLDRSQLPPR 104
Cdd:cd18161    78 TSGYAENAIEGGD 90

two component system response regulator;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  14 VVLVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDGVEKPPFLVVTDHLLPGtLQGADLANQLAARWPDLSIIVAS 93
Cdd:PRK15369    6 ILLVDDHELIINGIKNMLAPYPRYKIVGQVDNGLEVYNACRQLEPDIVILDLGLPG-MNGLDVIPQLHQRWPAMNILVLT 84

                  ..
gi 2445727555  94 GY 95
Cdd:PRK15369   85 AR 86

phosphoacceptor receiver (REC) domain of hybrid sensor histidine kinase/response regulators similar to Pseudomonas savastanoi blue-light-activated histidine kinase; Typically, two-component regulatory systems (TCSs) consist of a sensor (histidine kinase) that responds to specific input(s) by modifying the output of a cognate response regulator (RR). TCSs allow organisms to sense and respond to changes in environmental conditions. Hybrid sensor histidine kinase (HK)/response regulators contain all the elements of a classical TCS in a single polypeptide chain. Pseudomonas savastanoi blue-light-activated histidine kinase is a photosensitive HK and RR that is involved in increased bacterial virulence upon exposure to light. RRs share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  14 VVLVEDNEFLLEVMIGHLECYGAVCKAfgtADGASSYLDGVEKPPF--LVVTDHLLPGTLQGADLANQLAARWPDLSIIV 91
Cdd:cd18161     1 VLVVEDDPDVRRLTAEVLEDLGYTVLE---AASGDEALDLLESGPDidLLVTDVIMPGGMNGSQLAEEARRRRPDLKVLL 77

                          90
                  ....*....|...
gi 2445727555  92 ASGYLDRSQLPPR 104
Cdd:cd18161    78 TSGYAENAIEGGD 90

DNA-binding transcriptional response regulator, NtrC family, contains REC, AAA-type ATPase, and a Fis-type DNA-binding domains [Signal transduction mechanisms];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  10 QEKTVVLVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDgvEKPPFLVVTDHLLPGtLQGADLANQLAARWPDLSI 89
Cdd:COG2204     1 SMARILVVDDDPDIRRLLKELLERAGYEVETAASGEEALALLR--EEPPDLVLLDLRMPG-MDGLELLRELRALDPDLPV 77

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 2445727555  90 IVASGYLDRSQLpprKKTI------FLPKPWLPGGLEKAI 123
Cdd:COG2204    78 ILLTGYGDVETA---VEAIkagafdYLTKPFDLEELLAAV 114

phosphoacceptor receiver (REC) domain of response regulators (RRs) and pseudo response regulators (PRRs); Two-component systems (TCSs) involving a sensor and a response regulator are used by bacteria to adapt to changing environments. Processes regulated by two-component systems in bacteria include sporulation, pathogenicity, virulence, chemotaxis, and membrane transport. Response regulators (RRs) share the common phosphoacceptor REC domain and different effector/output domains such as DNA, RNA, ligand-binding, protein-binding, or enzymatic domains. Response regulators regulate transcription, post-transcription or post-translation, or have functions such as methylesterases, adenylate or diguanylate cyclase, c-di-GMP-specific phosphodiesterases, histidine kinases, serine/threonine protein kinases, and protein phosphatases, depending on their output domains. The function of some output domains are still unknown. TCSs are found in all three domains of life - bacteria, archaea, and eukaryotes, however, the presence and abundance of particular RRs vary between the lineages. Archaea encode very few RRs with DNA-binding output domains; most are stand-alone REC domains. Among eukaryotes, TCSs are found primarily in protozoa, fungi, algae, and green plants. REC domains function as phosphorylation-mediated switches within RRs, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  16 LVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDgvEKPPFLVVTDHLLPGtLQGADLANQLAARWPDLSIIVASGY 95
Cdd:cd00156     2 IVDDDPAIRELLKSLLEREGYEVDTAADGEEALELLR--EERPDLVLLDLMMPG-MDGLELLRKLRELPPDIPVIVLTAK 78

                  ...
gi 2445727555  96 LDR 98
Cdd:cd00156    79 ADE 81

phosphoacceptor receiver (REC) domain of VirG-like OmpR family response regulators; VirG is part of the VirA/VirG two-component system that regulates the expression of virulence (vir) genes. The histidine kinase VirA senses a phenolic wound response signal, undergoes autophosphorylation, and phosphorelays to the VirG response regulator, which induces transcription of the vir regulon. VirG belongs to the OmpR family of DNA-binding response regulators that contain N-terminal receiver (REC) and C-terminal DNA-binding winged helix-turn-helix effector domains. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  13 TVVLVEDNEFLLEVMIGHLECYGAvcKAFGTADGASSYLDGVEKPPFLVVTDHLLPGTlQGADLANQLAARwPDLSIIVA 92
Cdd:cd17594     1 HVLVVDDDAAMRHLLILYLRERGF--DVTAAADGAEEARLMLHRRVDLVLLDLRLGQE-SGLDLLRTIRAR-SDVPIIII 76

                  ..
gi 2445727555  93 SG 94
Cdd:cd17594    77 SG 78

DNA-binding response regulator, OmpR family, contains REC and winged-helix (wHTH) domain [Signal transduction mechanisms, Transcription];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  12 KTVVLVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDgvEKPPFLVVTDHLLPGtLQGADLANQLAARWPDLSIIV 91
Cdd:COG0745     2 PRILVVEDDPDIRELLADALEREGYEVDTAADGEEALELLE--EERPDLILLDLMLPG-MDGLEVCRRLRARPSDIPIIM 78

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 2445727555  92 ASGyldRSQLPPRKKTI------FLPKPWLPGGLEKAILA 125
Cdd:COG0745    79 LTA---RDDEEDRVRGLeagaddYLTKPFDPEELLARIRA 115

histidine kinase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  13 TVVLVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDGvEKPPFLVVTDHLLPGTLQGADLANQLAARWPDLSIIVA 92
Cdd:PRK13557  417 TILIVDDRPDVAELARMILEDFGYRTLVASNGREALEILDS-HPEVDLLFTDLIMPGGMNGVMLAREARRRQPKIKVLLT 495

                  ....*..
gi 2445727555  93 SGYLDRS 99
Cdd:PRK13557  496 TGYAEAS 502

phosphoacceptor receiver (REC) domain of hydrogen uptake protein regulator (HupR) and similar domains; This family is composed of mostly uncharacterized response regulators with similarity to the REC domains of response regulator components of two-component systems that regulates hydrogenase activity, including HupR and HoxA. HupR is part of the HupT/HupR system that controls the synthesis of the membrane-bound [NiFe]hydrogenase, HupSL, of the photosynthetic bacterium Rhodobacter capsulatus. It contains an N-terminal REC domain, a central sigma-54 interaction domain that lacks ATPase activity, and a C-terminal DNA-binding domain. Members of this family contain a REC domain and various output domains including the cyclase homology domain (CHD) and the c-di-GMP phosphodiesterase domains, HD-GYP and EAL. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  12 KTVVLVEDnefllEVMIghLECYGAVCKAFG----TADGASSYLDGVEKPPF-LVVTDHLLPGtLQGADLANQLAARWPD 86
Cdd:cd17569     1 PTILLVDD-----EPNI--LKALKRLLRREGyevlTATSGEEALEILKQEPVdVVISDQRMPG-MDGAELLKRVRERYPD 72

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 2445727555  87 LSIIVASGYLDRSQLpprKKTI-------FLPKPWLPGGLEKAI 123
Cdd:cd17569    73 TVRILLTGYADLDAA---IEAInegeiyrFLTKPWDDEELKETI 113

phosphoacceptor receiver (REC) domain of hydrogen uptake protein regulator (HupR); Members of this subfamily are response regulator components of two-component systems that regulates hydrogenase activity, including HupR and HoxA. HupR is part of the HupT/HupR system that controls the synthesis of the membrane-bound [NiFe]hydrogenase, HupSL, of the photosynthetic bacterium Rhodobacter capsulatus. It belongs to the nitrogen regulatory protein C (NtrC) family of response regulators, which activate transcription by RNA polymerase (RNAP) in response to a change in the environment. HupR is an unusual member of this family as it activates transcription when unphosphorylated, and transcription is inhibited by phosphorylation. Proteins in this subfamily contain an N-terminal REC domain, a central sigma-54 interaction domain that lacks ATPase activity, and a C-terminal DNA-binding domain. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  13 TVVLVEDNEFLLEVMIGHLECYGAVCKAfGTADGASSYLDgvEKPPFLVVTDHLLPGTlQGADLANQLAARWPDLSIIVA 92
Cdd:cd17596     2 TILVVDDEVRSLEALRRTLEEDFDVLTA-ASAEEALAILE--EEWVQVILCDQRMPGT-TGVEFLKEVRERWPEVVRIII 77

                          90       100       110
                  ....*....|....*....|....*....|....*..
gi 2445727555  93 SGYLDRSQLpprkktI----------FLPKPWLPGGL 119
Cdd:cd17596    78 SGYTDSEDI------IagineagiyqYLTKPWHPDQL 108

phosphoacceptor receiver (REC) domain of NarL (Nitrate/Nitrite response regulator L) family response regulators; The NarL family is one of the more abundant families of DNA-binding response regulators (RRs). Members of the NarL family contain a REC domain and a helix-turn-helix (HTH) DNA-binding output domain, with a majority of members containing a LuxR-type HTH domain. They function as transcriptional regulators. REC domains function as phosphorylation-mediated switches within response regulators, but some also transfer phosphoryl groups in multistep phosphorelays.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2445727555  14 VVLVEDNEFLLEVMIGHLECYGAVCKAFGTADGASSYLDGVEKPPFLVVTDHLLPGtLQGADLANQLAARWPDLSIIVAS 93
Cdd:cd17535     1 VLIVDDHPLVREGLRRLLESEPDIEVVGEAADGEEALALLRELRPDVVLMDLSMPG-MDGIEALRRLRRRYPDLKVIVLT 79

                  ....
gi 2445727555  94 GYLD 97
Cdd:cd17535    80 AHDD 83