Annotations: 4GCZ

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
B	HisKA	e4gczB3	A: alpha duplicates or obligate multimers	X: ROP-like	H: Homodimeric domain of signal transducing histidine kinase (From Topology)	T: Homodimeric domain of signal transducing histidine kinase	F: HisKA	ECOD (1.6)
B	HATPase_c	e4gczB2	A: a+b two layers	X: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase-like	H: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase (From Topology)	T: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase	F: HATPase_c	ECOD (1.6)
B	PAS	e4gczB1	A: a+b three layers	X: Profilin-like	H: sensor domains (From Topology)	T: sensor domains	F: PAS	ECOD (1.6)
A	HisKA	e4gczA6	A: alpha duplicates or obligate multimers	X: ROP-like	H: Homodimeric domain of signal transducing histidine kinase (From Topology)	T: Homodimeric domain of signal transducing histidine kinase	F: HisKA	ECOD (1.6)
A	HATPase_c	e4gczA1	A: a+b two layers	X: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase-like	H: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase (From Topology)	T: ATPase domain of HSP90 chaperone/DNA topoisomerase II/histidine kinase	F: HATPase_c	ECOD (1.6)
A	PAS	e4gczA5	A: a+b three layers	X: Profilin-like	H: sensor domains (From Topology)	T: sensor domains	F: PAS	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
B	3.30.450.20	Alpha Beta	2-Layer Sandwich	Beta-Lactamase	PAS domain	CATH (4.3.0)
B	1.10.287.130	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	Signal transduction histidine kinase, dimerisation/phosphotransfer (DHp) domain	CATH (4.3.0)
B	3.30.565.10	Alpha Beta	2-Layer Sandwich	Heat Shock Protein 90	Histidine kinase-like ATPase, C-terminal domain	CATH (4.3.0)
A	3.30.450.20	Alpha Beta	2-Layer Sandwich	Beta-Lactamase	PAS domain	CATH (4.3.0)
A	6.10.250.2580	Special	Helix non-globular	Single alpha-helices involved in coiled-coils or other helix-helix interfaces		CATH (4.3.0)
A	1.10.287.130	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	Signal transduction histidine kinase, dimerisation/phosphotransfer (DHp) domain	CATH (4.3.0)
A	3.30.565.10	Alpha Beta	2-Layer Sandwich	Heat Shock Protein 90	Histidine kinase-like ATPase, C-terminal domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF00512	His Kinase A (phospho-acceptor) domain (HisKA)	His Kinase A (phospho-acceptor) domain	Dimerisation and phospho-acceptor domain of histidine kinases.	Domain
A, B	PF13426	PAS domain (PAS_9)	PAS domain	This domain is found in many signalling proteins in which it functions as a sensor domain. It recognises FMN, Zn(II), FAD and riboflavin (MAtilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043).	Domain
A, B	PF02518	Histidine kinase-, DNA gyrase B-, and HSP90-like ATPase (HATPase_c)	Histidine kinase-, DNA gyrase B-, and HSP90-like ATPase	This family represents the structurally related ATPase domains of histidine kinase, DNA gyrase B and HSP90.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	Blue-light photoreceptor, Sensor protein fixL	molecular transducer activity photoreceptor activity signaling receptor activity binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding adenyl nucleotide binding ATP binding molecular transducer activity photoreceptor activity signaling receptor activity binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding molecular sensor activity catalytic activity, acting on a protein kinase activity protein kinase activity transferase activity phosphotransferase activity, nitrogenous group as acceptor phosphotransferase activity, alcohol group as acceptor protein histidine kinase activity transferase activity, transferring phosphorus-containing groups phosphorelay sensor kinase activity molecular function regulator activity catalytic activity cation binding metal ion binding histidine phosphotransfer kinase activity	cellular response to stimulus regulation of biological process phosphorelay signal transduction system regulation of cellular process response to stimulus signaling biological regulation intracellular signal transduction cell communication cellular process signal transduction RNA metabolic process regulation of primary metabolic process nucleobase-containing compound metabolic process cellular response to stimulus regulation of biological process phosphorelay signal transduction system regulation of cellular process response to stimulus signaling biological regulation intracellular signal transduction cell communication cellular process signal transduction RNA metabolic process regulation of primary metabolic process nucleobase-containing compound metabolic process RNA biosynthetic process nucleic acid biosynthetic process DNA-templated transcription regulation of RNA metabolic process regulation of nucleobase-containing compound metabolic process regulation of RNA biosynthetic process regulation of biosynthetic process primary metabolic process regulation of macromolecule metabolic process nucleobase-containing compound biosynthetic process gene expression macromolecule biosynthetic process nucleic acid metabolic process regulation of gene expression biosynthetic process metabolic process regulation of macromolecule biosynthetic process regulation of DNA-templated transcription macromolecule metabolic process regulation of metabolic process nitrogen cycle metabolic process nitrogen fixation	cell periphery cellular anatomical structure plasma membrane membrane

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR035965	PAS domain superfamily	Homologous Superfamily
A, B	IPR001610	PAC motif	Repeat
A, B	IPR036513	STAS domain superfamily	Homologous Superfamily
A, B	IPR000700	PAS-associated, C-terminal	Domain
A, B	IPR000014	PAS domain	Domain
A, B	IPR002645	STAS domain	Domain
A, B	IPR051932	Bacterial Stress Response Regulators	Family
A, B	IPR013767	PAS fold	Domain
A, B	IPR000014	PAS domain	Domain
A, B	IPR004358	Signal transduction histidine kinase-related protein, C-terminal	Domain
A, B	IPR036097	Signal transduction histidine kinase, dimerisation/phosphoacceptor domain superfamily	Homologous Superfamily
A, B	IPR053564	Sensor kinase FixL-like	Family
A, B	IPR036890	Histidine kinase/HSP90-like ATPase superfamily	Homologous Superfamily
A, B	IPR003661	Signal transduction histidine kinase, dimerisation/phosphoacceptor domain	Domain
A, B	IPR035965	PAS domain superfamily	Homologous Superfamily
A, B	IPR001610	PAC motif	Repeat
A, B	IPR000700	PAS-associated, C-terminal	Domain
A, B	IPR005467	Histidine kinase domain	Domain

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.