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UniProtKB/Swiss-Prot P08686: Variant p.Met283Leu

Steroid 21-hydroxylase
Gene: CYP21A2
Variant information

Variant position:  283
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  LP/P [Disclaimer]
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 Methionine (M) to Leucine (L) at position 283 (M283L, p.Met283Leu).
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:  Similar physico-chemical property. Both residues are medium size and hydrophobic.
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  2
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 AH3.
Any additional useful information about the variant.



Sequence information

Variant position:  283
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  494
The length of the canonical sequence.

Location on the sequence:   GVAQPSMEEGSGQLLEGHVH  M AAVDLLIGGTETTANTLSWA
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                         GVAQPSMEEGSGQLLEGHVHMAAVDLLIGGTETTANTLSWA

                              RVGRLRAEEGCGQLLEGHVHMSVVDLFIGGTETTATTLSWA

Mouse                         GVEKQRDGKDEERLHEGHVHMSVVDLFIGGTETTATTLSWA

Rat                           GVEKQRDARDPGQLHERHVHMSVVDLFVGGTETTAATLSWA

Pig                           EAGRQRVEEGQGQLLEGHVHMSVVDLFIGGTETTANTLSWA

Bovine                        GVGRQRVEEGPGQLLEGHVHMSVVDLFIGGTETTASTLSWA

Cat                           GMGKPKVEKGHGRLLEGHVHMSVVDLFIGGTETTATTLSWA

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 – 494 Steroid 21-hydroxylase
Mutagenesis 268 – 268 S -> CMT. No loss of function.
Mutagenesis 281 – 281 V -> I. Normal KM but 50% reduced Vmax.
Mutagenesis 281 – 281 V -> T. Normal KM but 10% reduced Vmax.
Helix 278 – 309


Literature citations

Non-classical 21-hydroxylase deficiency in children: association of adrenocorticotropic hormone-stimulated 17-hydroxyprogesterone with the risk of compound heterozygosity with severe mutations.
Ezquieta B.; Cueva E.; Varela J.; Oliver A.; Fernandez J.; Jariego C.;
Acta Paediatr. 91:892-898(2002)
Cited for: VARIANTS AH3 LEU-30; ASN-172; LEU-281; LEU-283; TRP-356 AND SER-453;

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.