UniProtKB/Swiss-Prot P16442: Variant p.Pro234Ala

Histo-blood group ABO system transferase
Gene: ABO
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Variant information Variant position:

234 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant:

LB/B The variants are classified into three categories: LP/P, LB/B and US.

LP/P: likely pathogenic or pathogenic.
LB/B: likely benign or benign.
US: uncertain significance

Residue change:

From Proline (P) to Alanine (A) at position 234 (P234A, p.Pro234Ala). 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 medium size and hydrophobic (P) to small size and hydrophobic (A) 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 ABO define the ABO blood group system [MIM:616093]. The ABO blood group system is one of the most important blood group systems in transfusion medicine. The ABO blood group involves 3 carbohydrate antigens: A, B, and H. A, B, and AB individuals express a glycosyltransferase activity that converts the H antigen to the A antigen (by addition of UDP-GalNAc) or to the B antigen (by addition of UDP-Gal). There are only 4 amino acid differences between A and B transferases in the catalytic domain, two of which (Leu266Met and Gly268Ala) are primarily responsible for the substrate specificity. The group O phenotype results from variations in ABO that cause a loss of glycosyltransferase activity. The most common group O allele results from a single nucleotide deletion near the 5' end of the gene (NM_020469.2:c.261del) that causes a frameshift and early termination with no active enzyme production (p.Thr88Profs*31). Additional information on the polymorphism described.
Variant description:

In allele B(A). Any additional useful information about the variant.

Sequence information Variant position:

234 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length:

354 The length of the canonical sequence.
Location on the sequence:

MEFRDHVGVEILTPLFGTLH P GFYGSSREAFTYERRPQSQA 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.
Residue conservation:

The multiple alignment of the region surrounding the variant against various orthologous sequences.

Human                         MEFRDHVGVEILTPLFGTLHPGFYGSSREAFTYERRPQSQA

Mouse                         MKFSDHVGVEILSTFFGTLHPGFYSSSREAFTYERRPQSQA

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.

Type	Positions	Description
Chain	1 – 354	Histo-blood group ABO system transferase
Chain	54 – 354	Fucosylglycoprotein alpha-N-acetylgalactosaminyltransferase soluble form
Topological domain	54 – 354	Lumenal
Binding site	233 – 233
Binding site	245 – 245
Mutagenesis	214 – 214	M -> TV. Alters substrate specificity so that both UDP-N-acetyl-D-galactosamine and UDP-galactose are utilized.
Mutagenesis	234 – 234	P -> S. Altered substrate specificity in group B transferase.
Turn	234 – 238

Literature citations
The molecular basis for the B(A) allele: an amino acid alteration in the human histoblood group B alpha-(1,3)-galactosyltransferase increases its intrinsic alpha-(1,3)-N-acetylgalactosaminyltransferase activity.
Yu L.C.; Lee H.L.; Chan Y.S.; Lin M.;
Biochem. Biophys. Res. Commun. 262:487-493(1999)
Cited for: POLYMORPHISM; VARIANT ALA-234;

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.