Reviewed, UniProtKB/Swiss-Prot P00736 (C1R_HUMAN)

Names and origin

Protein names

Recommended name:
    Complement C1r subcomponent
    EC=3.4.21.41
Alternative name(s):
    Complement component 1, r subcomponent
Cleaved into the following 2 chains:
    1- Recommended name:
            Complement C1r subcomponent heavy chain
    2- Recommended name:
            Complement C1r subcomponent light chain

Gene names

Name:

C1R

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	705 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	C1r B chain is a serine protease that combines with C1q and C1s to form C1, the first component of the classical pathway of the complement system.
Catalytic activity	Selective cleavage of Lys(or Arg)-|-Ile bond in complement subcomponent C1s to form the active form of C1s (EC 3.4.21.42).
Subunit structure	C1 is a calcium-dependent trimolecular complex of C1q, C1r and C1s in the molar ration of 1:2:2. C1r is a dimer of identical chains, each of which is activated by cleavage into two chains, A and B, connected by disulfide bonds.
Post-translational modification	The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.
Polymorphism	Complement component C1r deficiency [MIM:216950] leads to the failure of the classical complement system activation pathway (C1 deficiency). Individuals with C1 deficiency are highly susceptible to infections by microorganisms and have greater risk in developing autoimmune diseases such as systemic lupus erythematosus (SLE).
Sequence similarities	Belongs to the peptidase S1 family. Contains 2 CUB domains. Contains 1 EGF-like domain. Contains 1 peptidase S1 domain. Contains 2 Sushi (CCP/SCR) domains.

Ontologies

Keywords
Biological process	Complement pathway Immune response Innate immunity
Coding sequence diversity	Polymorphism
Domain	EGF-like domain Repeat Signal Sushi
Molecular function	Hydrolase Protease Serine protease
PTM	Disulfide bond Glycoprotein Hydroxylation Phosphoprotein
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Uncategorized	complement component C1r activity Inferred from Experiment. Source: Reactome
Biological process	complement activation, classical pathway Inferred from electronic annotation. Source: UniProtKB-KW innate immune response Inferred from electronic annotation. Source: UniProtKB-KW proteolysis Inferred from electronic annotation. Source: InterPro
Cellular component	extracellular region Non-traceable author statement. Source: UniProtKB
Molecular function	calcium ion binding Inferred from electronic annotation. Source: InterPro serine-type endopeptidase activity Traceable author statement. Source: ProtInc
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 17

17

Ref.7

Chain

18 – 705

688

Complement C1r subcomponent

PRO_0000027577

Chain

18 – 463

446

Complement C1r subcomponent heavy chain

PRO_0000027578

Chain

464 – 705

242

Complement C1r subcomponent light chain

PRO_0000027579

Regions

Domain

18 – 141

124

CUB 1

Domain

142 – 190

49

EGF-like; calcium-binding Potential

Domain

193 – 305

113

CUB 2

Domain

307 – 373

67

Sushi 1

Domain

374 – 449

76

Sushi 2

Domain

464 – 702

239

Peptidase S1

Sites

Active site

502

1

Charge relay system

Active site

557

1

Charge relay system

Active site

654

1

Charge relay system

Amino acid modifications

Modified residue

167

1

(3R)-3-hydroxyasparagine

Modified residue

206

1

Phosphoserine; by CK2

Glycosylation

125

1

N-linked (GlcNAc...) Ref.11

Glycosylation

221

1

N-linked (GlcNAc...) Ref.11

Glycosylation

514

1

N-linked (GlcNAc...) Ref.11

Glycosylation

581

1

N-linked (GlcNAc...)

Disulfide bond

71 ↔ 89

Probable

Disulfide bond

146 ↔ 165

Disulfide bond

161 ↔ 174

Disulfide bond

176 ↔ 189

Disulfide bond

193 ↔ 220

Probable

Disulfide bond

250 ↔ 268

Probable

Disulfide bond

309 ↔ 358

Disulfide bond

338 ↔ 371

Disulfide bond

376 ↔ 429

Disulfide bond

406 ↔ 447

Disulfide bond

451 ↔ 577

Interchain (between heavy and light chains)

Disulfide bond

620 ↔ 639

Disulfide bond

650 ↔ 680

Natural variations

Natural variant

131

1

Y → H Ref.3

VAR_018667

Natural variant

152

1

S → L Common polymorphism. dbSNP rs1801046. Ref.3 Ref.2 Ref.6 Ref.16

VAR_016103

Natural variant

163

1

H → Y Ref.3

VAR_018668

Natural variant

184

1

E → K Ref.3

VAR_018669

Natural variant

186

1

T → R: dbSNP rs4519167. Ref.3 Ref.2 Ref.6 Ref.1

VAR_047933

Natural variant

261

1

G → R: dbSNP rs3813728.

VAR_018670

Secondary structure

1

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705

Helix Strand Turn

Details...

Turn

145 – 147

3

Turn

150 – 152

3

Beta strand

156 – 158

3

Beta strand

162 – 168

7

Beta strand

171 – 175

5

Beta strand

319 – 323

5

Beta strand

326 – 328

3

Beta strand

333 – 338

6

Beta strand

342 – 348

7

Beta strand

350 – 352

3

Beta strand

354 – 358

5

Beta strand

364 – 366

3

Beta strand

370 – 373

4

Beta strand

385 – 392

8

Beta strand

401 – 406

6

Turn

408 – 410

3

Beta strand

411 – 414

4

Beta strand

426 – 429

4

Beta strand

433 – 440

8

Beta strand

446 – 449

4

Beta strand

478 – 492

15

Turn

493 – 495

3

Beta strand

496 – 499

4

Helix

501 – 503

3

Beta strand

518 – 522

5

Helix

526 – 531

6

Beta strand

537 – 542

6

Beta strand

548 – 552

5

Beta strand

559 – 565

7

Helix

582 – 585

4

Beta strand

590 – 595

6

Beta strand

608 – 615

8

Helix

617 – 621

5

Beta strand

636 – 641

6

Helix

643 – 650

8

Beta strand

657 – 662

6

Turn

663 – 666

4

Beta strand

667 – 674

8

Turn

678 – 683

6

Beta strand

684 – 689

6

Helix

690 – 693

4

Helix

694 – 700

7

Sequences

	Sequence		Length	Mass (Da)
	P00736-1 [UniParc]. Last modified December 16, 2008. Version 2. Checksum: B45D120201061462	FASTA	705	80,119
	10 20 30 40 50 60 MWLLYLLVPA LFCRAGGSIP IPQKLFGEVT SPLFPKPYPN NFETTTVITV PTGYRVKLVF 70 80 90 100 110 120 QQFDLEPSEG CFYDYVKISA DKKSLGRFCG QLGSPLGNPP GKKEFMSQGN KMLLTFHTDF 130 140 150 160 170 180 SNEENGTIMF YKGFLAYYQA VDLDECASRS KSGEEDPQPQ CQHLCHNYVG GYFCSCRPGY 190 200 210 220 230 240 ELQEDTHSCQ AECSSELYTE ASGYISSLEY PRSYPPDLRC NYSIRVERGL TLHLKFLEPF 250 260 270 280 290 300 DIDDHQQVHC PYDQLQIYAN GKNIGEFCGK QRPPDLDTSS NAVDLLFFTD ESGDSRGWKL 310 320 330 340 350 360 RYTTEIIKCP QPKTLDEFTI IQNLQPQYQF RDYFIATCKQ GYQLIEGNQV LHSFTAVCQD 370 380 390 400 410 420 DGTWHRAMPR CKIKDCGQPR NLPNGDFRYT TTMGVNTYKA RIQYYCHEPY YKMQTRAGSR 430 440 450 460 470 480 ESEQGVYTCT AQGIWKNEQK GEKIPRCLPV CGKPVNPVEQ RQRIIGGQKA KMGNFPWQVF 490 500 510 520 530 540 TNIHGRGGGA LLGDRWILTA AHTLYPKEHE AQSNASLDVF LGHTNVEELM KLGNHPIRRV 550 560 570 580 590 600 SVHPDYRQDE SYNFEGDIAL LELENSVTLG PNLLPICLPD NDTFYDLGLM GYVSGFGVME 610 620 630 640 650 660 EKIAHDLRFV RLPVANPQAC ENWLRGKNRM DVFSQNMFCA GHPSLKQDAC QGDSGGVFAV 670 680 690 700 RDPNTDRWVA TGIVSWGIGC SRGYGFYTKV LNYVDWIKKE MEEED

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Nucleotide sequence of the cDNA coding for human complement C1r." Leytus S.P., Kurachi K., Sakariassen K.S., Davie E.W. Biochemistry 25:4855-4863(1986) [PubMed: 3021205] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], VARIANT ARG-186.
[2]	"Cloning and sequencing of full-length cDNA encoding the precursor of human complement component C1r." Journet A., Tosi M. Biochem. J. 240:783-787(1986) [PubMed: 3030286] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], VARIANTS LEU-152 AND ARG-186.
[3]	"The human complement component C1R gene: the exon-intron structure and the molecular basis of allelic diversity." Nakagawa M., Yuasa I., Irizawa Y., Umetsu K. Ann. Hum. Genet. 67:207-215(2003) [PubMed: 12914573] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], VARIANTS HIS-131; LEU-152; TYR-163; LYS-184; ARG-186 AND ARG-261.
[4]	"The full-ORF clone resource of the German cDNA consortium." Bechtel S., Rosenfelder H., Duda A., Schmidt C.P., Ernst U., Wellenreuther R., Mehrle A., Schuster C., Bahr A., Blocker H., Heubner D., Hoerlein A., Michel G., Wedler H., Kohrer K., Ottenwalder B., Poustka A., Wiemann S., Schupp I. BMC Genomics 8:399-399(2007) [PubMed: 17974005] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Colon endothelium.
[5]	"The finished DNA sequence of human chromosome 12." Scherer S.E., Muzny D.M., Buhay C.J., Chen R., Cree A., Ding Y., Dugan-Rocha S., Gill R., Gunaratne P., Harris R.A., Hawes A.C., Hernandez J., Hodgson A.V., Hume J., Jackson A., Khan Z.M., Kovar-Smith C., Lewis L.R. , Lozado R.J., Metzker M.L., Milosavljevic A., Miner G.R., Montgomery K.T., Morgan M.B., Nazareth L.V., Scott G., Sodergren E., Song X.-Z., Steffen D., Lovering R.C., Wheeler D.A., Worley K.C., Yuan Y., Zhang Z., Adams C.Q., Ansari-Lari M.A., Ayele M., Brown M.J., Chen G., Chen Z., Clerc-Blankenburg K.P., Davis C., Delgado O., Dinh H.H., Draper H., Gonzalez-Garay M.L., Havlak P., Jackson L.R., Jacob L.S., Kelly S.H., Li L., Li Z., Liu J., Liu W., Lu J., Maheshwari M., Nguyen B.-V., Okwuonu G.O., Pasternak S., Perez L.M., Plopper F.J.H., Santibanez J., Shen H., Tabor P.E., Verduzco D., Waldron L., Wang Q., Williams G.A., Zhang J., Zhou J., Allen C.C., Amin A.G., Anyalebechi V., Bailey M., Barbaria J.A., Bimage K.E., Bryant N.P., Burch P.E., Burkett C.E., Burrell K.L., Calderon E., Cardenas V., Carter K., Casias K., Cavazos I., Cavazos S.R., Ceasar H., Chacko J., Chan S.N., Chavez D., Christopoulos C., Chu J., Cockrell R., Cox C.D., Dang M., Dathorne S.R., David R., Davis C.M., Davy-Carroll L., Deshazo D.R., Donlin J.E., D'Souza L., Eaves K.A., Egan A., Emery-Cohen A.J., Escotto M., Flagg N., Forbes L.D., Gabisi A.M., Garza M., Hamilton C., Henderson N., Hernandez O., Hines S., Hogues M.E., Huang M., Idlebird D.G., Johnson R., Jolivet A., Jones S., Kagan R., King L.M., Leal B., Lebow H., Lee S., LeVan J.M., Lewis L.C., London P., Lorensuhewa L.M., Loulseged H., Lovett D.A., Lucier A., Lucier R.L., Ma J., Madu R.C., Mapua P., Martindale A.D., Martinez E., Massey E., Mawhiney S., Meador M.G., Mendez S., Mercado C., Mercado I.C., Merritt C.E., Miner Z.L., Minja E., Mitchell T., Mohabbat F., Mohabbat K., Montgomery B., Moore N., Morris S., Munidasa M., Ngo R.N., Nguyen N.B., Nickerson E., Nwaokelemeh O.O., Nwokenkwo S., Obregon M., Oguh M., Oragunye N., Oviedo R.J., Parish B.J., Parker D.N., Parrish J., Parks K.L., Paul H.A., Payton B.A., Perez A., Perrin W., Pickens A., Primus E.L., Pu L.-L., Puazo M., Quiles M.M., Quiroz J.B., Rabata D., Reeves K., Ruiz S.J., Shao H., Sisson I., Sonaike T., Sorelle R.P., Sutton A.E., Svatek A.F., Svetz L.A., Tamerisa K.S., Taylor T.R., Teague B., Thomas N., Thorn R.D., Trejos Z.Y., Trevino B.K., Ukegbu O.N., Urban J.B., Vasquez L.I., Vera V.A., Villasana D.M., Wang L., Ward-Moore S., Warren J.T., Wei X., White F., Williamson A.L., Wleczyk R., Wooden H.S., Wooden S.H., Yen J., Yoon L., Yoon V., Zorrilla S.E., Nelson D., Kucherlapati R., Weinstock G., Gibbs R.A. Nature 440:346-351(2006) [PubMed: 16541075] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[6]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], VARIANTS LEU-152 AND ARG-186. Tissue: Skin.
[7]	"Complete amino acid sequence of the A chain of human complement-classical-pathway enzyme C1r." Arlaud G.J., Willis A.C., Gagnon J. Biochem. J. 241:711-720(1987) [PubMed: 3036070] [Abstract] Cited for: PROTEIN SEQUENCE OF 18-463.
[8]	"Complete amino acid sequence of the catalytic chain of human complement subcomponent C1-r." Arlaud G.J., Gagnon J. Biochemistry 22:1758-1764(1983) [PubMed: 6303394] [Abstract] Cited for: PROTEIN SEQUENCE OF 464-705.
[9]	"Identification of erythro-beta-hydroxyasparagine in the EGF-like domain of human C1r." Arlaud G.J., van Dorsselaer A., Bell A., Mancini M., Aude C., Gagnon J. FEBS Lett. 222:129-134(1987) [PubMed: 2820791] [Abstract] Cited for: PROTEIN SEQUENCE OF 152-186, HYDROXYLATION.
[10]	"Identification of a cryptic protein kinase CK2 phosphorylation site in human complement protease Clr, and its use to probe intramolecular interaction." Pelloux S., Thielens N.M., Hudry-Clergeon G., Petillot Y., Filhol O., Arlaud G.J. FEBS Lett. 386:15-20(1996) [PubMed: 8635594] [Abstract] Cited for: PROTEIN SEQUENCE OF 133-137; 187-211 AND 609-613, PHOSPHORYLATION.
[11]	"Human plasma N-glycoproteome analysis by immunoaffinity subtraction, hydrazide chemistry, and mass spectrometry." Liu T., Qian W.-J., Gritsenko M.A., Camp D.G. II, Monroe M.E., Moore R.J., Smith R.D. J. Proteome Res. 4:2070-2080(2005) [PubMed: 16335952] [Abstract] Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-125; ASN-221 AND ASN-514, MASS SPECTROMETRY. Tissue: Plasma.
[12]	"Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry." Chen R., Jiang X., Sun D., Han G., Wang F., Ye M., Wang L., Zou H. J. Proteome Res. 8:651-661(2009) [PubMed: 19159218] [Abstract] Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-514, MASS SPECTROMETRY. Tissue: Liver.
[13]	"Solution structure of the epidermal growth factor (EGF)-like module of human complement protease C1r, an atypical member of the EGF family." Bersch B., Hernandez J.-F., Marion D., Arlaud G.J. Biochemistry 37:1204-1214(1998) [PubMed: 9477945] [Abstract] Cited for: STRUCTURE BY NMR OF 140-192.
[14]	"The crystal structure of the zymogen catalytic domain of complement protease C1r reveals that a disruptive mechanical stress is required to trigger activation of the C1 complex." Budayova-Spano M., Lacroix M., Thielens N.M., Arlaud G.J., Fontecilla-Camps J.-C., Gaboriaud C. EMBO J. 21:231-239(2002) [PubMed: 11823416] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.9 ANGSTROMS) OF 307-702.
[15]	"Monomeric structures of the zymogen and active catalytic domain of complement protease c1r: further insights into the c1 activation mechanism." Budayova-Spano M., Grabarse W., Thielens N.M., Hillen H., Lacroix M., Schmidt M., Fontecilla-Camps J.-C., Arlaud G.J., Gaboriaud C. Structure 10:1509-1519(2002) [PubMed: 12429092] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (3.2 ANGSTROMS) OF 375-702.
[16]	"A common amino acid polymorphism in complement component C1R." Nothen M.M., Dewald G. Hum. Mol. Genet. 3:217-217(1994) [PubMed: 8162045] [Abstract] Cited for: VARIANT LEU-152.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

M14058 mRNA. Translation: AAA51851.1.
X04701 mRNA. Translation: CAA28407.1.
AB083037 Genomic DNA. Translation: BAC19850.2.
AC094008 Genomic DNA. No translation available.
AC140077 Genomic DNA. No translation available.
CR749540 mRNA. Translation: CAH18343.1.
BC035220 mRNA. Translation: AAH35220.1.

IPI

IPI00296165.

PIR

C1HURB. A24170.

RefSeq

NP_001724.3.

UniGene

Hs.524224

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1APQ	NMR	-	A	140-192	[»]
1GPZ	X-ray	2.90	A/B	307-705	[»]
1MD7	X-ray	3.20	A	375-702	[»]
1MD8	X-ray	2.80	A	375-703	[»]
2QY0	X-ray	2.60	A/C	309-463	[»]
			B/D	464-705	[»]

ModBase

Search...

PTM databases

PhosphoSite

P00736.

Proteomic databases

PeptideAtlas

P00736.

Genome annotation databases

GeneID

715.

KEGG

hsa:715.

Organism-specific databases

GeneCards

GC12M007058.

H-InvDB

HIX0036748.
HIX0060170.

HGNC

HGNC:1246. C1R.

HPA

HPA001551.

MIM

216950. gene+phenotype.

PharmGKB

PA25635.

GenAtlas

Search...

Phylogenomic databases

HOVERGEN

P00736.

Enzyme and pathway databases

BRENDA

3.4.21.41. 247.

Reactome

REACT_6900. Signaling in Immune system.

Gene expression databases

CleanEx

HS_C1R.

Family and domain databases

InterPro

IPR000859. CUB.
IPR013032. EGF-like_reg_CS.
IPR000152. EGF-type_Asp/Asn_hydroxyl_CS.
IPR001881. EGF_Ca_bd.
IPR013091. EGF_Ca_bd_2.
IPR018097. EGF_Ca_bd_CS.
IPR018114. Peptidase_S1/S6_AS.
IPR001254. Peptidase_S1_S6.
IPR001314. Peptidase_S1A.
IPR000436. Sushi_SCR_CCP.
[Graphical view]

Gene3D

G3DSA:2.60.120.290. CUB. 2 hits.

Pfam

PF00431. CUB. 2 hits.
PF07645. EGF_CA. 1 hit.
PF00084. Sushi. 2 hits.
PF00089. Trypsin. 1 hit.
[Graphical view]

PRINTS

PR00722. CHYMOTRYPSIN.

SMART

SM00032. CCP. 2 hits.
SM00042. CUB. 2 hits.
SM00179. EGF_CA. 1 hit.
SM00020. Tryp_SPc. 1 hit.
[Graphical view]

PROSITE

PS00010. ASX_HYDROXYL. 1 hit.
PS01180. CUB. 2 hits.
PS00022. EGF_1. False negative.
PS01186. EGF_2. 1 hit.
PS50026. EGF_3. False negative.
PS01187. EGF_CA. 1 hit.
PS50923. SUSHI. 2 hits.
PS50240. TRYPSIN_DOM. 1 hit.
PS00134. TRYPSIN_HIS. False negative.
PS00135. TRYPSIN_SER. 1 hit.
[Graphical view]

ProtoNet

Search...

Other Resources

DrugBank

DB00054. Abciximab.
DB00051. Adalimumab.
DB00092. Alefacept.
DB00087. Alemtuzumab.
DB00074. Basiliximab.
DB00112. Bevacizumab.
DB00002. Cetuximab.
DB00111. Daclizumab.
DB00095. Efalizumab.
DB00005. Etanercept.
DB00056. Gemtuzumab ozogamicin.
DB00078. Ibritumomab.
DB00028. Immune globulin.
DB00075. Muromonab.
DB00108. Natalizumab.
DB00110. Palivizumab.
DB00073. Rituximab.
DB00081. Tositumomab.
DB00072. Trastuzumab.

NextBio

2906.

SOURCE

Search...

Entry information

Entry name

C1R_HUMAN

Accession

Primary (citable) accession number: P00736
Secondary accession number(s): A6NJQ8, Q68D77, Q8J012

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	December 16, 2008
Last modified:	June 16, 2009
This is version 127 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)