UniProtKB/Swiss-Prot P54132: Variant p.Thr843Ile

Bloom syndrome protein
Gene: BLM
Chromosomal location: 15q26.1
Variant information

Variant position:  843
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Disease [Disclaimer]
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 Threonine (T) to Isoleucine (I) at position 843 (T843I, p.Thr843Ile).
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 polar (T) to medium size and hydrophobic (I)
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

Involvement in disease:  Bloom syndrome (BLM) [MIM:210900]: An autosomal recessive disorder. It is characterized by proportionate pre- and postnatal growth deficiency, sun-sensitive telangiectatic hypo- and hyperpigmented skin, predisposition to malignancy, and chromosomal instability. Note=The disease is caused by mutations affecting the gene represented in this entry.
The name and a short description of the disease associated with the variant. For more information about the disease, the user can refer to OMIM, following the link provided after the disease acronym.

Variant description:  In BLM.
Any additional useful information about the variant.



Sequence information

Variant position:  843
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  1417
The length of the canonical sequence.

Location on the sequence:   SVPVMALTATANPRVQKDIL  T QLKILRPQVFSMSFNRHNLK
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                         SVPVMALTATANPRVQKDILTQLKILRPQVFSMSFNRHNLK

Mouse                         SVPVMALTATANPRVQKDILTQLKILRPQVFSMSFNRHNLK

Xenopus laevis                SVPMMALTATANPRVKKDILNQLKMTKPQIFTMSFNRDNLK

Caenorhabditis elegans        PVPIIALTATATPKIVTDARDHLKMQNSKLFISSFVRDNLK

Drosophila                    NVPTIALTATATPRVRLDILAQLNLKNCKWFLSSFNRSNLR

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 1 – 1417 Bloom syndrome protein
Domain 676 – 851 Helicase ATP-binding
Modified residue 863 – 863 N6-acetyllysine
Helix 835 – 845


Literature citations

The Bloom's syndrome gene product is homologous to RecQ helicases.
Ellis N.A.; Groden J.; Ye T.-Z.; Straughen J.; Lennon D.J.; Ciocci S.; Proytcheva M.; German J.;
Cell 83:655-666(1995)
Cited for: NUCLEOTIDE SEQUENCE [MRNA]; VARIANTS BLM ARG-672; ILE-843 AND SER-1055;

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.