Annotations: 4BIX

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	HAMP,HisKA	e4bixA1	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: HAMP,HisKA	ECOD (1.6)
A	HATPase_c	e4bixA2	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	HisKA	e4bixB2	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	e4bixB1	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)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.287.130	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	Signal transduction histidine kinase, dimerisation/phosphotransfer (DHp) domain	CATH (utative)
A	3.30.565.10	Alpha Beta	2-Layer Sandwich	Heat Shock Protein 90	Histidine kinase-like ATPase, C-terminal domain	CATH (utative)
B	1.10.287.130	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	Signal transduction histidine kinase, dimerisation/phosphotransfer (DHp) domain	CATH (utative)
B	3.30.565.10	Alpha Beta	2-Layer Sandwich	Heat Shock Protein 90	Histidine kinase-like ATPase, C-terminal domain	CATH (utative)

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	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	SENSOR PROTEIN CPXA	binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding phosphoric ester hydrolase activity phosphoprotein phosphatase activity catalytic activity, acting on a protein hydrolase activity, acting on ester bonds phosphatase activity hydrolase activity catalytic activity molecular sensor activity 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 identical protein binding protein binding	cell adhesion involved in biofilm formation cell adhesion cell aggregation biofilm formation cell-substrate adhesion cellular process aggregation of unicellular organisms submerged biofilm formation cellular response to stimulus cellular response to stress response to stimulus response to stress cellular response to cell envelope stress response to radiation cell adhesion involved in biofilm formation cell adhesion cell aggregation biofilm formation cell-substrate adhesion cellular process aggregation of unicellular organisms submerged biofilm formation cellular response to stimulus cellular response to stress response to stimulus response to stress cellular response to cell envelope stress response to radiation response to abiotic stimulus regulation of biological process regulation of cellular process signaling biological regulation signal transduction cell communication	cell periphery plasma membrane membrane cellular anatomical entity

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR004358	Signal transduction histidine kinase-related protein, C-terminal	Domain
A, B	IPR038515	Two-component sensor protein CpxA, periplasmic domain superfamily	Homologous Superfamily
A, B	IPR036097	Signal transduction histidine kinase, dimerisation/phosphoacceptor domain superfamily	Homologous Superfamily
A, B	IPR003660	HAMP domain	Domain
A, B	IPR050398	Bacterial Sensor Histidine Kinase	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	IPR003594	Histidine kinase/HSP90-like ATPase domain	Domain
A, B	IPR005467	Histidine kinase domain	Domain
A, B	IPR032404	Two-component sensor protein CpxA, periplasmic 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.