UniProtKB/Swiss-Prot P11226: Variant p.Gly54Asp

Mannose-binding protein C
Gene: MBL2
Chromosomal location: 10q11.2
Variant information

Variant position:  54
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Polymorphism
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants have been found in patients and disease-association is reported in literature. However, this classification is not a definitive assessment of variant pathogenicity.
  • Polymorphism: No disease-association has been reported.
  • Unclassified: Variants have been found in patients but disease-association remains unclear.

Residue change:  From Glycine (G) to Aspartate (D) at position 54 (G54D, p.Gly54Asp).
Indicates the amino acid change of the variant. The one-letter and three-letter codes for amino acids used in UniProtKB/Swiss-Prot are those adopted by the commission on Biochemical Nomenclature of the IUPAC-IUB.

Physico-chemical properties:  Change from glycine (G) to medium size and acidic (D)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -1
The score within a Blosum matrix for the corresponding wild-type to variant amino acid change. The log-odds score measures the logarithm for the ratio of the likelihood of two amino acids appearing by chance. The Blosum62 substitution matrix is used. This substitution matrix contains scores for all possible exchanges of one amino acid with another:
  • Lowest score: -4 (low probability of substitution).
  • Highest score: 11 (high probability of substitution).
More information can be found on the following page

Polymorphism:  Genetic variations in MBL2 influence susceptibility to hepatitis B virus (HBV) infection [MIM:610424].Genetic variations in MBL2 are responsible for mannose-binding protein deficiency [MIM:614372]. This condition is defined as MBL2 protein level of less than 100 ng/ml, is present in about 5% of people of European descent and in about 10% of sub-Saharan Africans. Most MBL2-deficient adults appear healthy, but low levels of MBL2 are associated with increased risk of infection in toddlers, in cancer patients undergoing chemotherapy, and in organ-transplant patients receiving immunosuppressive drugs, particularly recipients of liver transplants. There is an association between low levels of MBL2 and a defect of opsonization which results in susceptibility to frequent and chronic infections (PubMed:1675710). Functional MBL2 deficiency may be associated with protection against tuberculosis caused by Mycobacterium africanum but not by Mycobacterium tuberculosis, as observed in studies on Ghanaian patients with pulmonary tuberculosis (PubMed:21695215). -
Additional information on the polymorphism described.

Variant description:  Polymorphism associated with mannose-binding protein deficiency and recurrent infections.
Any additional useful information about the variant.

Other resources:  
Links to websites of interest for the variant.



Sequence information

Variant position:  54
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  248
The length of the canonical sequence.

Location on the sequence:   AVIACSSPGINGFPGKDGRD  G TKGEKGEPGQGLRGLQGPPG
The residue change on the sequence. Unless the variant is located at the beginning or at the end of the protein sequence, both residues upstream (20) and downstream (20) of the variant will be shown.

Sequence annotation in neighborhood:  
The regions or sites of interest surrounding the variant. In general the features listed are posttranslational modifications, binding sites, enzyme active sites, local secondary structure or other characteristics reported in the cited references. The "Sequence annotation in neighborhood" lines have a fixed format:
  • Type: the type of sequence feature.
  • Positions: endpoints of the sequence feature.
  • Description: contains additional information about the feature.

TypePositionsDescription
Chain 21 – 248 Mannose-binding protein C
Domain 42 – 99 Collagen-like
Modified residue 47 – 47 Hydroxyproline
Modified residue 73 – 73 Hydroxyproline


Literature citations

Different molecular events result in low protein levels of mannan-binding lectin in populations from South-East Africa and South America.
Madsen H.O.; Satz M.L.; Hogh B.; Svejgaard A.; Garred P.;
J. Immunol. 161:3169-3175(1998)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]; VARIANTS CYS-52; ASP-54 AND GLU-57;

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)
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]; VARIANT ASP-54;

Restricted polymorphisms of the mannose-binding lectin gene in a population of Papua New Guinea.
Jueliger S.; Kremsner P.G.; Alpers M.P.; Reeder J.C.; Kun J.F.J.;
Mutat. Res. 505:87-91(2002)
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-59; VARIANT ASP-54;

Molecular basis of opsonic defect in immunodeficient children.
Sumiya M.; Super M.; Tabona P.; Levinsky R.J.; Arai T.; Turner M.W.; Summerfield J.A.;
Lancet 337:1569-1570(1991)
Cited for: VARIANT ASP-54; ASSOCIATION WITH MANNOSE-BINDING PROTEIN DEFICIENCY AND SUSCEPTIBILITY TO CHRONIC INFECTIONS;

High frequencies in African and non-African populations of independent mutations in the mannose binding protein gene.
Lipscombe R.J.; Sumiya M.; Hill A.V.S.; Lau Y.L.; Levinsky R.J.; Summerfield J.A.; Turner M.W.;
Hum. Mol. Genet. 1:709-715(1992)
Cited for: VARIANTS ASP-54 AND GLU-57; ASSOCIATION WITH MANNOSE-BINDING PROTEIN DEFICIENCY;

Distinct and overlapping functions of allelic forms of human mannose binding protein.
Super M.; Gillies S.D.; Foley S.; Sastry K.; Schweinle J.E.; Silverman V.J.; Ezekowitz R.A.;
Nat. Genet. 2:50-55(1992)
Cited for: VARIANT ASP-54;

Genotyping of the three major allelic variants of the human mannose-binding lectin gene by denaturing gradient gel electrophoresis.
Gabolde M.; Muralitharan S.; Besmond C.;
Hum. Mutat. 14:80-83(1999)
Cited for: VARIANTS CYS-52; ASP-54 AND GLU-57;

Mannose binding lectin genotypes influence recovery from hepatitis B virus infection.
Thio C.L.; Mosbruger T.; Astemborski J.; Greer S.; Kirk G.D.; O'Brien S.J.; Thomas D.L.;
J. Virol. 79:9192-9196(2005)
Cited for: INVOLVEMENT IN SUSCEPTIBILITY TO HBV INFECTION; VARIANTS CYS-52; ASP-54 AND GLU-57;

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