Reviewed, UniProtKB/Swiss-Prot P26460 (KCRB_SQUAC)

Names and origin

Protein names	Recommended name:     Creatine kinase B-type     EC=2.7.3.2 Alternative name(s):     Creatine kinase B chain     B-CK
Organism	Squalus acanthias (Spiny dogfish)
Taxonomic identifier	7797 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Chondrichthyes › Elasmobranchii › Squalea › Hypnosqualea › Squaliformes › Squaloidei › Squalidae › Squalus

Protein attributes

Sequence length	52 AA.
Sequence status	Fragments.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Reversibly catalyzes the transfer of phosphate between ATP and various phosphogens (e.g. creatine phosphate). Creatine kinase isoenzymes play a central role in energy transduction in tissues with large, fluctuating energy demands, such as skeletal muscle, heart, brain and spermatozoa. The isoform-specific function of B creatine kinase may be to provide a system for the rapid regeneration of metabolic energy for sodium transport.
Catalytic activity	ATP + creatine = ADP + phosphocreatine.
Subunit structure	Dimer of identical or non-identical chains. With MM being the major form in skeletal muscle and myocardium, MB existing in myocardium, and BB existing in many tissues, especially brain.
Subcellular location	Basal cell membrane. Note: Basal membrane of the sodium chloride-secreting epithelia.
Tissue specificity	Creatine kinase B is the major isoform present in the rectal gland.
Sequence similarities	Belongs to the ATP:guanido phosphotransferase family.

Ontologies

Keywords
Cellular component	Cell membrane Membrane
Coding sequence diversity	Polymorphism
Ligand	ATP-binding Nucleotide-binding
Molecular function	Kinase Transferase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular component	basal plasma membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW creatine kinase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	‹1 – ›52	›52	Creatine kinase B-type		PRO_0000211972
Sites
	Binding site	13	1	ATP By similarity
	Binding site	47	1	ATP By similarity
Natural variations
	Natural variant	3	1	V → I
	Natural variant	5	1	T → S
	Natural variant	10	1	K → S
	Natural variant	13	1	R → K
	Natural variant	16	1	S → Q
Experimental info
	Sequence uncertainty	38	1
	Non-adjacent residues	28 – 29	2
	Non-terminal residue	1	1
	Non-terminal residue	52	1

Sequences

	Sequence		Length	Mass (Da)
	P26460-1 [UniParc]. Last modified August 1, 1992. Version 1. Checksum: 3BC2C989F21CFF30	FASTA	52	5,778
	10 20 30 40 50 AKVLTLDLYK KLRDKSTPSG FTLDDIIQNE HLGYVLTCPS NLGTXLRAXV HV

References

[1]	"Purification and localization of brain-type creatine kinase in sodium chloride transporting epithelia of the spiny dogfish, Squalus acanthias." Friedman D.L., Roberts R. J. Biol. Chem. 267:4270-4276(1992) [PubMed: 1310991] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Rectal gland.

Cross-references

Sequence databases
PIR	A42272. B42272.
3D structure databases
HSSP	HSSP built from PDB template 1CRK based on UniProtKB P11009.
ModBase	Search...
Phylogenomic databases
HOVERGEN	P26460.
Enzyme and pathway databases
BRENDA	2.7.3.2. 981.
Family and domain databases
InterPro	IPR000749. ATP-guanido_PTrfase. [Graphical view]
PANTHER	PTHR11547. ATP-gua_Ptrans. 1 hit.
Pfam	PF00217. ATP-gua_Ptrans. 1 hit. PF02807. ATP-gua_PtransN. 1 hit. [Graphical view]
PROSITE	PS00112. GUANIDO_KINASE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

KCRB_SQUAC

Accession

Primary (citable) accession number: P26460

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1992
Last sequence update:	August 1, 1992
Last modified:	March 3, 2009
This is version 50 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)