P00709 (LALBA_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Alpha-lactalbumin

Alternative name(s):
Lactose synthase B protein
Lysozyme-like protein 7

Gene names

Name:	LALBA
Synonyms:	LYZL7

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	142 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	Regulatory subunit of lactose synthase, changes the substrate specificity of galactosyltransferase in the mammary gland making glucose a good acceptor substrate for this enzyme. This enables LS to synthesize lactose, the major carbohydrate component of milk. In other tissues, galactosyltransferase transfers galactose onto the N-acetylglucosamine of the oligosaccharide chains in glycoproteins.
Subunit structure	Lactose synthase (LS) is a heterodimer of a catalytic component, beta1,4-galactosyltransferase (beta4Gal-T1) and a regulatory component, alpha-lactalbumin (LA).
Subcellular location	Secreted.
Tissue specificity	Mammary gland specific. Secreted in milk.
Sequence similarities	Belongs to the glycosyl hydrolase 22 family.

Ontologies

Keywords
Biological process	Lactose biosynthesis
Cellular component	Secreted
Coding sequence diversity	Polymorphism
Domain	Signal
Ligand	Calcium
Molecular function	Milk protein
PTM	Disulfide bond Glycoprotein
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological process	cell-cell signaling Traceable author statement. Source: ProtInc defense response to bacterium Traceable author statement. Source: ProtInc induction of apoptosis Traceable author statement. Source: ProtInc lactose biosynthetic process Traceable author statement. Source: ProtInc signal transduction Traceable author statement. Source: ProtInc
Cellular component	extracellular space Traceable author statement. Source: ProtInc
Molecular function	calcium ion binding Inferred from electronic annotation. Source: InterPro lactose synthase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 19

19

Ref.7

Chain

20 – 142

123

Alpha-lactalbumin

PRO_0000018444

Regions

Calcium binding

97 – 108

12

Amino acid modifications

Glycosylation

64

1

N-linked (GlcNAc...) Ref.10

Glycosylation

90

1

N-linked (GlcNAc...); partial; atypical Ref.9

Disulfide bond

25 ↔ 139

Disulfide bond

47 ↔ 130

Disulfide bond

80 ↔ 96

Disulfide bond

92 ↔ 110

Natural variations

Natural variant

46

1

I → V. Ref.15
Corresponds to variant rs2232565 [ dbSNP | Ensembl ].

VAR_024526

Experimental info

Sequence conflict

99

1

F → K AA sequence Ref.8

Secondary structure

1

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142

Helix Strand Turn

Details...

Helix

24 – 30

7

Helix

32 – 34

3

Helix

37 – 39

3

Helix

42 – 53

12

Beta strand

60 – 62

3

Beta strand

67 – 69

3

Turn

70 – 73

4

Turn

76 – 78

3

Beta strand

79 – 81

3

Helix

96 – 100

5

Helix

105 – 117

13

Turn

118 – 120

3

Helix

121 – 124

4

Helix

134 – 137

4

Sequences

	Sequence		Length	Mass (Da)
	P00709 [UniParc]. Last modified July 21, 1986. Version 1. Checksum: 647F448733B06D65	FASTA	142	16,225
	10 20 30 40 50 60 MRFFVPLFLV GILFPAILAK QFTKCELSQL LKDIDGYGGI ALPELICTMF HTSGYDTQAI 70 80 90 100 110 120 VENNESTEYG LFQISNKLWC KSSQVPQSRN ICDISCDKFL DDDITDDIMC AKKILDIKGI 130 140 DYWLAHKALC TEKLEQWLCE KL

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Comparison of the nucleotide sequence of cloned human and guinea-pig pre-alpha-lactalbumin cDNA with that of chick pre-lysozyme cDNA suggests evolution from a common ancestral gene." Hall L., Craig R.K., Edbrooke M.R., Campbell P.N. Nucleic Acids Res. 10:3503-3515(1982) [PubMed: 6285305] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Organization and sequence of the human alpha-lactalbumin gene." Hall L., Emery D.C., Davies M.S., Parker D., Craig R.K. Biochem. J. 242:735-742(1987) [PubMed: 2954544] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]	"Analysis of flanking sequence of human alpha-lactalbumin containing a putative locus control region." Fujiwara Y., Takahashi R., Hirabayashi M., Ueda M., Muramatsu T., Yamanaka H., Sekikawa K. Submitted (OCT-2000) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[4]	"Cloning of human full open reading frames in Gateway(TM) system entry vector (pDONR201)." Halleck A., Ebert L., Mkoundinya M., Schick M., Eisenstein S., Neubert P., Kstrang K., Schatten R., Shen B., Henze S., Mar W., Korn B., Zuo D., Hu Y., LaBaer J. Submitted (JUN-2004) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[5]	Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., Turner R. , Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., Venter J.C. Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases 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]. Tissue: Brain.
[7]	"The complete amino-acid sequence of human alpha-lactalbumin." Findlay J.B.C., Brew K. Eur. J. Biochem. 27:65-86(1972) [PubMed: 5049057] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-142.
[8]	"Identification of a new molecular form of human alpha-lactalbumin." Maynard F. J. Dairy Res. 59:425-429(1992) [PubMed: 1401360] [Abstract] Cited for: PROTEIN SEQUENCE OF 78-81 AND 90-112. Tissue: Milk.
[9]	"An unusual glycosylation site in alpha-lactalbumin from human milk." Cavaletto M., Giuffrida M.G., Giunta C., Conti A. Protein Sci. 4 Suppl. 1:119-119(1995) Cited for: GLYCOSYLATION AT ASN-90.
[10]	"Identification of N-linked glycoproteins in human milk by hydrophilic interaction liquid chromatography and mass spectrometry." Picariello G., Ferranti P., Mamone G., Roepstorff P., Addeo F. Proteomics 8:3833-3847(2008) [PubMed: 18780401] [Abstract] Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-64, MASS SPECTROMETRY. Tissue: Milk.
[11]	"Crystal structure of human alpha-lactalbumin at 1.7-A resolution." Acharya K.R., Ren J.S., Stuart D.I., Phillips D.C., Fenna R.E. J. Mol. Biol. 221:571-581(1991) [PubMed: 1920433] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS).
[12]	"Alpha-lactalbumin possesses a distinct zinc binding site." Ren J.S., Stuart D.I., Acharya K.R. J. Biol. Chem. 268:19292-19298(1993) [PubMed: 8366079] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS).
[13]	"Structural evidence for the presence of a secondary calcium binding site in human alpha-lactalbumin." Chandra N., Brew K., Acharya K.R. Biochemistry 37:4767-4772(1998) [PubMed: 9537992] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS).
[14]	"Crystallographic evaluation of internal motion of human alpha-lactalbumin refined by full-matrix least-squares method." Harata K., Abe Y., Muraki M. J. Mol. Biol. 287:347-358(1999) [PubMed: 10080897] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.15 ANGSTROMS).
[15]	"Detection of a single nucleotide polymorphism in the human alpha-lactalbumin gene: implications for human milk proteins." Chowanadisai W., Kelleher S.L., Nemeth J.F., Yachetti S., Kuhlman C.F., Jackson J.G., Davis A.M., Lien E.L., Loennerdal B. J. Nutr. Biochem. 16:272-278(2005) [PubMed: 15866226] [Abstract] Cited for: VARIANT VAL-46, MASS SPECTROMETRY.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

J00270 mRNA. Translation: AAA60345.1.
X05153 Genomic DNA. Translation: CAA28799.1.
X05153 Genomic DNA. Translation: CAA28800.1.
AB049976 Genomic DNA. Translation: BAC06860.1.
CR541987 mRNA. Translation: CAG46784.1.
CR542017 mRNA. Translation: CAG46814.1.
CH471111 Genomic DNA. Translation: EAW57990.1.
BC069103 mRNA. Translation: AAH69103.1.
BC112316 mRNA. Translation: AAI12317.1.
BC112318 mRNA. Translation: AAI12319.1.

IPI

IPI00019524.

PIR

LAHU. A27880.

RefSeq

NP_002280.1. NM_002289.2.

UniGene

Hs.72938.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1A4V	X-ray	1.80	A	20-142	[»]
1B9O	X-ray	1.15	A	20-142	[»]
1CB3	NMR	-	A	120-129	[»]
1HML	X-ray	1.70	A	1-142	[»]

ProteinModelPortal

P00709.

SMR

P00709. Positions 20-142.

ModBase

Search...

Protein-protein interaction databases

STRING

P00709.

Protein family/group databases

Allergome

1289. Hom s ALA.

Polymorphism databases

DMDM

126001.

Proteomic databases

PRIDE

P00709.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

Ensembl

ENST00000301046; ENSP00000301046; ENSG00000167531.

GeneID

3906.

KEGG

hsa:3906.

UCSC

uc001rrt.1. human.

Organism-specific databases

CTD

3906.

GeneCards

GC12M048927.

H-InvDB

HIX0036821.

HGNC

HGNC:6480. LALBA.

HPA

HPA029856.

MIM

149750. gene.

neXtProt

NX_P00709.

PharmGKB

PA30269.

GenAtlas

Search...

Phylogenomic databases

eggNOG

prNOG15569.

GeneTree

ENSGT00550000074398.

HOGENOM

HBG505822.

HOVERGEN

HBG052297.

InParanoid

P00709.

OMA

NICDISC.

OrthoDB

EOG43JC60.

PhylomeDB

P00709.

Gene expression databases

ArrayExpress

P00709.

Bgee

P00709.

CleanEx

HS_LALBA.

Genevestigator

P00709.

GermOnline

ENSG00000167531. Homo sapiens.

Family and domain databases

InterPro

IPR001916. Glyco_hydro_22.
IPR019799. Glyco_hydro_22_CS.
IPR000545. Lactalbumin.
IPR023346. Lysozyme-like_dom.
[Graphical view]

KO

K00704.

PANTHER

PTHR11407:SF5. Lactalbumin. 1 hit.

Pfam

PF00062. Lys. 1 hit.
[Graphical view]

PRINTS

PR00136. LACTALBUMIN.
PR00135. LYZLACT.

SMART

SM00263. LYZ1. 1 hit.
[Graphical view]

SUPFAM

SSF53955. SSF53955. 1 hit.

PROSITE

PS00128. LACTALBUMIN_LYSOZYME_1. 1 hit.
PS51348. LACTALBUMIN_LYSOZYME_2. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

NextBio

15335.

SOURCE

Search...

Entry information

Entry name

LALBA_HUMAN

Accession

Primary (citable) accession number: P00709
Secondary accession number(s): Q6FGX0, Q9UDK4

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	July 21, 1986
Last modified:	January 25, 2012
This is version 127 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.