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UniProtKB/Swiss-Prot P21980: Variant p.Ile331Asn

Protein-glutamine gamma-glutamyltransferase 2
Gene: TGM2
Variant information

Variant position:  331
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  US
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 Isoleucine (I) to Asparagine (N) at position 331 (I331N, p.Ile331Asn).
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 (I) to medium size and polar (N)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -3
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

Variant description:  In patients with early-onset diabetes type 2; unknown pathological significance.
Any additional useful information about the variant.



Sequence information

Variant position:  331
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  687
The length of the canonical sequence.

Location on the sequence:   LLIEYFRNEFGEIQGDKSEM  I WNFHCWVESWMTRPDLQPGY
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                         LLIEYFRNEFGEIQGDKSEMIWNFHCWVESWMTRPDLQPGY

Mouse                         LLIEYFRNEFGELESNKSEMIWNFHCWVESWMTRPDLQPGY

Rat                           LLIEYFRNEYGELESNKSEMIWNFHCWVESWMTRPDLQPGY

Bovine                        LLIEYFRNEFGEIQSDKSEMIWNFHCWVESWMTRPDLQPGY

Chicken                       LVIDRYLSETGMEERRSTDMIWNFHCWVECWMTRPDLAPGY

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 2 – 687 Protein-glutamine gamma-glutamyltransferase 2
Active site 335 – 335
Disulfide bond 230 – 370 Alternate
Alternative sequence 287 – 349 VLRCLGIPTRVVTNYNSAHDQNSNLLIEYFRNEFGEIQGDKSEMIWNFHCWVESWMTRPDLQP -> GELHAGMWVMSPGRGHEEHWSRNQDIPALVLPPATNTLNALCGLEPVTTLSGPLSNSHPSSGC. In isoform 3.
Mutagenesis 332 – 332 W -> F. In TG2-I; strongly reduced transamidase activity without affecting the isopeptidase activity.
Mutagenesis 332 – 332 W -> L. Abolished isopeptidase and transamidase activities.
Mutagenesis 334 – 334 F -> L. Abolished isopeptidase and transamidase activities.
Mutagenesis 337 – 337 W -> F. Reduced isopeptidase and transamidase activities.
Mutagenesis 337 – 337 W -> L. Abolished isopeptidase and transamidase activities.


Literature citations

Missense mutations in the TGM2 gene encoding transglutaminase 2 are found in patients with early-onset type 2 diabetes.
Porzio O.; Massa O.; Cunsolo V.; Colombo C.; Malaponti M.; Bertuzzi F.; Hansen T.; Johansen A.; Pedersen O.; Meschi F.; Terrinoni A.; Melino G.; Federici M.; Decarlo N.; Menicagli M.; Campani D.; Marchetti P.; Ferdaoussi M.; Froguel P.; Federici G.; Vaxillaire M.; Barbetti F.;
Hum. Mutat. 28:1150-1150(2007)
Cited for: VARIANTS ARG-330 AND ASN-331;

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.