SUPERFAMILY 1.75 HMM library and genome assignments server


Cytochrome b5-like heme/steroid binding domain superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   Alpha and beta proteins (a+b) [ 53931] (376)
Fold:   Cytochrome b5-like heme/steroid binding domain [ 55855]
Superfamily:   Cytochrome b5-like heme/steroid binding domain [ 55856] (2)
Families:   Cytochrome b5 [ 55857] (4)
  Steroid-binding domain [ 103222]


Superfamily statistics
Genomes (654) Uniprot 2014_06 PDB chains (SCOP 1.75)
Domains 8,674 10,602 34
Proteins 8,510 10,381 34


Functional annotation
General category Metabolism
Detailed category E- transfer

Document:
Function annotation of SCOP domain superfamilies

Gene Ontology (high-quality)

(show details)
GO termFDR (singleton)FDR (all)SDFO levelAnnotation (direct or inherited)
Biological Process (BP)single-organism metabolic process0.015037.643e-09Least InformativeInherited
Biological Process (BP)monocarboxylic acid metabolic process0.073591.503e-06Moderately InformativeInherited
Biological Process (BP)cellular lipid metabolic process0.007263.77e-15Moderately InformativeInherited
Biological Process (BP)fatty acid metabolic process0.00012580.0006374InformativeDirect
Molecular Function (MF)oxidoreductase activity0.0016610Moderately InformativeInherited
Molecular Function (MF)electron carrier activity1.225e-061.542e-09InformativeDirect
Molecular Function (MF)oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxyge0.00025111.828e-06Highly InformativeDirect

Document: GO annotation of SCOP domains

Gene Ontology (high-coverage)

(show details)
GO term FDR (all) SDFO level Annotation (direct or inherited)
Biological Process (BP) single-organism metabolic process 7.643e-09 Least Informative Direct
Biological Process (BP) biosynthetic process 0.00165 Least Informative Inherited
Biological Process (BP) developmental process 1 Least Informative Inherited
Biological Process (BP) organic cyclic compound metabolic process 1 Least Informative Inherited
Biological Process (BP) nitrogen compound metabolic process 0.9051 Least Informative Inherited
Biological Process (BP) lipid biosynthetic process 4.877e-12 Moderately Informative Direct
Biological Process (BP) monocarboxylic acid metabolic process 1.503e-06 Moderately Informative Direct
Biological Process (BP) cellular lipid metabolic process 3.77e-15 Moderately Informative Direct
Biological Process (BP) single-organism biosynthetic process 1.638e-06 Moderately Informative Direct
Biological Process (BP) reproduction 1 Moderately Informative Inherited
Biological Process (BP) organic hydroxy compound metabolic process 0.006319 Moderately Informative Inherited
Biological Process (BP) organic cyclic compound biosynthetic process 0.6568 Moderately Informative Inherited
Biological Process (BP) carbohydrate derivative metabolic process 0.2923 Moderately Informative Inherited
Biological Process (BP) fatty acid metabolic process 0.0006374 Informative Direct
Biological Process (BP) monocarboxylic acid biosynthetic process 5.528e-06 Informative Direct
Biological Process (BP) growth 0.1541 Informative Inherited
Biological Process (BP) organic hydroxy compound biosynthetic process 0.005817 Informative Inherited
Biological Process (BP) alcohol metabolic process 0.1494 Informative Inherited
Biological Process (BP) membrane lipid metabolic process 0.08459 Informative Inherited
Biological Process (BP) steroid biosynthetic process 0.0003822 Highly Informative Direct
Biological Process (BP) sterol metabolic process 1.68e-06 Highly Informative Direct
Biological Process (BP) unsaturated fatty acid metabolic process 1.033e-05 Highly Informative Direct
Biological Process (BP) alcohol biosynthetic process 0.02888 Highly Informative Inherited
Molecular Function (MF) binding 1 Least Informative Inherited
Molecular Function (MF) oxidoreductase activity 0 Moderately Informative Direct
Molecular Function (MF) electron carrier activity 1.542e-09 Informative Direct
Molecular Function (MF) tetrapyrrole binding 3.017e-06 Informative Direct
Molecular Function (MF) oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxyge 1.828e-06 Highly Informative Direct
Molecular Function (MF) heme binding 2.213e-06 Highly Informative Direct
Molecular Function (MF) oxidoreductase activity, acting on NAD(P)H 0.04735 Highly Informative Inherited
Cellular Component (CC) intracellular organelle part 1 Least Informative Inherited
Cellular Component (CC) intracellular membrane-bounded organelle 1 Least Informative Inherited
Cellular Component (CC) cytoplasmic part 0.09633 Least Informative Inherited
Cellular Component (CC) membrane 0.6274 Least Informative Inherited
Cellular Component (CC) endoplasmic reticulum 5.872e-10 Moderately Informative Direct
Cellular Component (CC) endomembrane system 0.0009187 Moderately Informative Direct
Cellular Component (CC) organelle membrane 3.09e-05 Moderately Informative Direct
Cellular Component (CC) endoplasmic reticulum membrane 2.301e-07 Informative Direct

Document: GO annotation of SCOP domains

Enzyme Commission (EC)

(show details)
EC termFDR (all)SDEO levelAnnotation (direct or inherited)
Enzyme Commission (EC)Oxidoreductases0Least InformativeDirect
Enzyme Commission (EC)Acting on a sulfur group of donors0.01363Moderately InformativeInherited
Enzyme Commission (EC)Acting on NADH or NADPH0.0902Moderately InformativeInherited
Enzyme Commission (EC)With NAD(+) or NADP(+) as acceptor0InformativeDirect
Enzyme Commission (EC)Nitrate reductase (NADH)0Highly InformativeDirect
Enzyme Commission (EC)Sulfite oxidase0Highly InformativeDirect
Enzyme Commission (EC)With a heme protein as acceptor2.642e-14Highly InformativeDirect
Enzyme Commission (EC)Nitrate reductase (NADPH)4.944e-10Highly InformativeDirect

Document: EC annotation of SCOP domains

Human Phenotype (HP)

(show details)
HP termFDR (all)SDHP levelAnnotation (direct or inherited)
Phenotypic Abnormality (PA)Abnormality of the genitourinary system0Least InformativeDirect

Document: HP annotation of SCOP domains

Worm Phenotype (WP)

(show details)
WP termFDR (all)SDWP levelAnnotation (direct or inherited)
Worm Phenotype (WP)organ system development variant0.004696Moderately InformativeInherited

Document: WP annotation of SCOP domains

Yeast Phenotype (YP)

(show details) Document: YP annotation of SCOP domains

Fly Phenotype (FP)

(show details)
FP termFDR (all)SDFP levelAnnotation (direct or inherited)
Fly Phenotype (FP)viable0Least InformativeDirect
Fly Phenotype (FP)fertile0Moderately InformativeDirect

Document: FP annotation of SCOP domains

Xenopus Anatomy (XA)

(show details)
XA termFDR (all)SDXA levelAnnotation (direct or inherited)
Xenopus ANatomical entity (XAN)genital system0Least InformativeDirect
Xenopus ANatomical entity (XAN)central nervous system0Least InformativeDirect
Xenopus ANatomical entity (XAN)male organism0Least InformativeDirect
Xenopus ANatomical entity (XAN)head0Least InformativeDirect
Xenopus ANatomical entity (XAN)gonad0Least InformativeDirect

Document: XA annotation of SCOP domains

Arabidopsis Plant Ontology (AP)

(show details) Document: AP annotation of SCOP domains

Enzyme Commission (EC)

(show details)
EC termFDR (all)SDEC levelAnnotation (direct or inherited)
Enzyme Commission (EC)Oxidoreductases0Least InformativeDirect
Enzyme Commission (EC)Acting on other nitrogenous compounds as donors0InformativeDirect
Enzyme Commission (EC)Acting on paired donors, with incorporation or reduction of molecular oxygen0.0006419InformativeDirect
Enzyme Commission (EC)Acting on a sulfur group of donors0.02515InformativeInherited
Enzyme Commission (EC)Acting on NADH or NADPH0.198InformativeInherited
Enzyme Commission (EC)With NAD(+) or NADP(+) as acceptor0Highly InformativeDirect
Enzyme Commission (EC)With oxygen as acceptor0Highly InformativeDirect
Enzyme Commission (EC)With a heme protein as acceptor7.561e-14Highly InformativeDirect

Document: EC annotation of SCOP domains

UniProtKB KeyWords (KW)

(show details)
KW termFDR (all)SDKW levelAnnotation (direct or inherited)
Biological processTransport0Least InformativeDirect
Biological processLipid metabolism0Moderately InformativeDirect
Biological processElectron transport0InformativeDirect
Biological processFatty acid metabolism3.607e-08InformativeDirect
Biological processNeurogenesis2.229e-05InformativeDirect
Biological processLipid biosynthesis0.11InformativeInherited
Biological processNitrate assimilation0Highly InformativeDirect
Biological processSphingolipid metabolism2.606e-08Highly InformativeDirect
Cellular componentMembrane0Least InformativeDirect
Cellular componentEndoplasmic reticulum0Moderately InformativeDirect
Cellular componentMitochondrion6.87e-06Moderately InformativeDirect
Cellular componentMicrosome2.964e-11Highly InformativeDirect
DomainTransmembrane0Least InformativeDirect
Molecular functionMetal-binding0Least InformativeDirect
Molecular functionFlavoprotein0Moderately InformativeDirect
Molecular functionIron0Moderately InformativeDirect
Molecular functionNAD4.991e-11Moderately InformativeDirect
Molecular functionHeme0InformativeDirect
Molecular functionMolybdenum0InformativeDirect
Molecular functionLipid-binding2.152e-12InformativeDirect
Molecular functionFAD4.203e-05InformativeDirect
Molecular functionSteroid-binding0Highly InformativeDirect
Post-translational modificationOxidoreductase0Moderately InformativeDirect
Post-translational modificationReceptor0.0002472Moderately InformativeDirect

Document: KW annotation of SCOP domains

UniProtKB UniPathway (UP)

(show details)
UP termFDR (all)SDUP levelAnnotation (direct or inherited)
UniPathway (UP)lipid metabolism2.702e-10Least InformativeDirect
UniPathway (UP)fatty acid metabolism0Moderately InformativeDirect
UniPathway (UP)lipid biosynthesis2.929e-12Moderately InformativeDirect
UniPathway (UP)energy metabolism2.819e-07Moderately InformativeDirect
UniPathway (UP)fatty acid biosynthesis0InformativeDirect

Document: UP annotation of SCOP domains

InterPro annotation
Cross references IPR001199 SSF55856 Protein matches
Abstract Cytochromes b5 are ubiquitous electron transport proteins found in animals, plants and yeasts [PubMed2752049]. The microsomal and mitochondrial variants are membrane-bound, while those from erythrocytes and other animal tissues are water-soluble [PubMed4030743, PubMed8439576].

The 3D structure of bovine cyt b5 is known, the fold belonging to the alpha+beta class, with 5 strands and 5 short helices forming a framework for supporting a central haem group [PubMed1167544]. The cytochrome b5 domain is similar to that of a number of oxidoreductases, such as plant and fungal nitrate reductases, sulphite oxidase, yeast flavocytochrome b2 (L-lactate dehydrogenase) and plant cyt b5/acyl lipid desaturase fusion protein.


InterPro database


PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Gene Ontology (high-quality) · Gene Ontology (high-coverage) · Enzyme Commission (EC) · Human Phenotype (HP) · Worm Phenotype (WP) · Yeast Phenotype (YP) · Fly Phenotype (FP) · Xenopus Anatomy (XA) · Arabidopsis Plant Ontology (AP) · Enzyme Commission (EC) · UniProtKB KeyWords (KW) · UniProtKB UniPathway (UP) ]

Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.


Alignments of sequences to 10 models in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.


Browse and view proteins in genomes which have different domain combinations including a Cytochrome b5-like heme/steroid binding domain domain.


Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.


Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 10 hidden Markov models representing the Cytochrome b5-like heme/steroid binding domain superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.


Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Gene Ontology (high-quality) · Gene Ontology (high-coverage) · Enzyme Commission (EC) · Human Phenotype (HP) · Worm Phenotype (WP) · Yeast Phenotype (YP) · Fly Phenotype (FP) · Xenopus Anatomy (XA) · Arabidopsis Plant Ontology (AP) · Enzyme Commission (EC) · UniProtKB KeyWords (KW) · UniProtKB UniPathway (UP) · Internal database links ]