DnaJ domain or J-domain. DnaJ/Hsp40 (heat shock protein 40) proteins are highly conserved and play crucial roles in protein translation, folding, unfolding, translocation, and degradation. They act primarily by stimulating the ATPase activity of Hsp70s, an important chaperonine family. Hsp40 proteins are characterized by the presence of a J domain, which mediates the interaction with Hsp70. They may contain other domains as well, and the architectures provide a means of classification.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
2GUZ_N          1 MTLDESCKILNIEEskgDLNMDKINNRFNYLFEVNDKEKGGSFYLQSKVYRAAERLKWELAQREK 65
Cdd:pfam03656  55 ISLDESCQILNVEE---DLNMEEVNKRYEHLFEVNDKSKGGSFYLQSKVYRAKERLDEELAIREK 116

Pam16; The Pam16 protein is the fifth essential subunit of the pre-sequence translocase-associated protein import motor (PAM). In Saccharomyces cerevisiae, Pam16 is required for preprotein translocation into the matrix, but not for protein insertion into the inner membrane. Pam16 has a degenerate J domain. J-domain proteins play important regulatory roles as co-chaperones, recruiting Hsp70 partners and accelerating the ATP-hydrolysis step of the chaperone cycle. Pam16's J-like domain strongly interacts with Pam18's J domain, leading to a productive interaction of Pam18 with mtHsp70 at the mitochondria import channel. Pam18 stimulates the ATPase activity of mtHsp70.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
2GUZ_N          1 MTLDESCKILNIEEskgDLNMDKINNRFNYLFEVNDKEKGGSFYLQSKVYRAAERLKWELAQREK 65
Cdd:pfam03656  55 ISLDESCQILNVEE---DLNMEEVNKRYEHLFEVNDKSKGGSFYLQSKVYRAKERLDEELAIREK 116

These ferredoxin reductases are related to the NADPH cytochrome p450 reductases (CYPOR), but lack the FAD-binding region connecting sub-domain. Ferredoxin-NADP+ reductase (FNR) is an FAD-containing enzyme that catalyzes the reversible electron transfer between NADP(H) and electron carrier proteins, such as ferredoxin and flavodoxin. Isoforms of these flavoproteins (i.e. having a non-covalently bound FAD as a prosthetic group) are present in chloroplasts, mitochondria, and bacteria in which they participate in a wide variety of redox metabolic pathways. The C-terminal domain contains most of the NADP(H) binding residues and the N-terminal domain interacts non-covalently with the isoalloxazine rings of the flavin molecule which lies largely in a large gap between the two domains. Ferredoxin-NADP+ reductase first accepts one electron from reduced ferredoxin to form a flavin semiquinone intermediate. The enzyme then accepts a second electron to form FADH2, which then transfers two electrons and a proton to NADP+ to form NADPH. CYPOR serves as an electron donor in several oxygenase systems and is a component of nitric oxide synthases, sulfite reducatase, and methionine synthase reductases. CYPOR transfers two electrons from NADPH to the heme of cytochrome p450 via FAD and FMN. CYPOR has a C-terminal FNR-like FAD and NAD binding module, an FMN-binding domain, and an additional connecting domain (inserted within the FAD binding region) that orients the FNR and FMN -binding domains. The C-terminal domain contains most of the NADP(H) binding residues, and the N-terminal domain interacts non-covalently with the isoalloxazine rings of the flavin molecule, which lies largely in a large gap betweed the two domains. Ferredoxin-NADP+ reductase first accepts one electron from reduced ferredoxin to form a flavin semiquinone intermediate. The enzyme then accepts a second electron to form FADH2 which then transfers two electrons and a proton to NADP+ to form NADPH.

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                ....*....|....*....|....*....|....*....|....*....|....*...
2GUZ_N        9 ILNIEESKGDLNMDKINNRFNYLFEVNDK-EKGGSFYLQSKVYRAAERLkWELAQREK 65
Cdd:cd06208 183 LLYDDELEKYPKQYPDNFRIDYAFSREQKnADGGKMYVQDRIAEYAEEI-WNLLDKDN 239

Pam16; The Pam16 protein is the fifth essential subunit of the pre-sequence translocase-associated protein import motor (PAM). In Saccharomyces cerevisiae, Pam16 is required for preprotein translocation into the matrix, but not for protein insertion into the inner membrane. Pam16 has a degenerate J domain. J-domain proteins play important regulatory roles as co-chaperones, recruiting Hsp70 partners and accelerating the ATP-hydrolysis step of the chaperone cycle. Pam16's J-like domain strongly interacts with Pam18's J domain, leading to a productive interaction of Pam18 with mtHsp70 at the mitochondria import channel. Pam18 stimulates the ATPase activity of mtHsp70.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*
2GUZ_N          1 MTLDESCKILNIEEskgDLNMDKINNRFNYLFEVNDKEKGGSFYLQSKVYRAAERLKWELAQREK 65
Cdd:pfam03656  55 ISLDESCQILNVEE---DLNMEEVNKRYEHLFEVNDKSKGGSFYLQSKVYRAKERLDEELAIREK 116

These ferredoxin reductases are related to the NADPH cytochrome p450 reductases (CYPOR), but lack the FAD-binding region connecting sub-domain. Ferredoxin-NADP+ reductase (FNR) is an FAD-containing enzyme that catalyzes the reversible electron transfer between NADP(H) and electron carrier proteins, such as ferredoxin and flavodoxin. Isoforms of these flavoproteins (i.e. having a non-covalently bound FAD as a prosthetic group) are present in chloroplasts, mitochondria, and bacteria in which they participate in a wide variety of redox metabolic pathways. The C-terminal domain contains most of the NADP(H) binding residues and the N-terminal domain interacts non-covalently with the isoalloxazine rings of the flavin molecule which lies largely in a large gap between the two domains. Ferredoxin-NADP+ reductase first accepts one electron from reduced ferredoxin to form a flavin semiquinone intermediate. The enzyme then accepts a second electron to form FADH2, which then transfers two electrons and a proton to NADP+ to form NADPH. CYPOR serves as an electron donor in several oxygenase systems and is a component of nitric oxide synthases, sulfite reducatase, and methionine synthase reductases. CYPOR transfers two electrons from NADPH to the heme of cytochrome p450 via FAD and FMN. CYPOR has a C-terminal FNR-like FAD and NAD binding module, an FMN-binding domain, and an additional connecting domain (inserted within the FAD binding region) that orients the FNR and FMN -binding domains. The C-terminal domain contains most of the NADP(H) binding residues, and the N-terminal domain interacts non-covalently with the isoalloxazine rings of the flavin molecule, which lies largely in a large gap betweed the two domains. Ferredoxin-NADP+ reductase first accepts one electron from reduced ferredoxin to form a flavin semiquinone intermediate. The enzyme then accepts a second electron to form FADH2 which then transfers two electrons and a proton to NADP+ to form NADPH.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*...
2GUZ_N        9 ILNIEESKGDLNMDKINNRFNYLFEVNDK-EKGGSFYLQSKVYRAAERLkWELAQREK 65
Cdd:cd06208 183 LLYDDELEKYPKQYPDNFRIDYAFSREQKnADGGKMYVQDRIAEYAEEI-WNLLDKDN 239