E249E252

E249E252 is a notation used in protein sequence annotations to denote a short motif consisting of consecutive glutamate residues at positions 249 to 252 in a given protein sequence. The letter E is the one-letter code for the amino acid glutamate, and the numerals indicate the standard residue numbering in the reference sequence. The motif describes a small acidic cluster within the protein, often located in loop regions or near the active site, where the collective negative charge of several glutamates can influence local structure or interactions.

Across different proteins, the exact occurrence of an E249E252 motif and its functional relevance vary. In some cases, such acidic clusters participate in metal ion coordination, stabilize transition states, or contribute to substrate binding through electrostatic effects. In others, the region may be neutralized or replaced by substitutions, which can modulate activity or stability. The motif can be identified by sequence alignment, structural data, or mutational studies that replace one or more Glu residues with other amino acids to assess functional impact.

Because E249E252 is a descriptive label rather than a fixed functional domain, it does not imply a universal role. It is used in protein-specific analyses to highlight a short acidic patch and may be discussed in the context of a particular protein family, structure, or research question.