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Enzymes, Moonlighting Enzymes, Pseudoenzymes: Members of a Protein Superfamily Can Have Similar Amino Acid Sequences but Different Functions
Author(s) -
Jeffery Constance
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.04059
Subject(s) - enzyme , peptide sequence , biochemistry , biology , amino acid , sequence (biology) , amino acid residue , protein superfamily , protein sequencing , superfamily , protein family , computational biology , structural classification of proteins database , protein structure , sequence alignment , genetics , gene
The functions of newly identified proteins are often estimated by sequence alignment with the sequences of proteins that have experimentally determined functions. However, members of a protein superfamily can share significant amino acid sequence identity but vary in the reaction catalyzed and/or the substrate used. In addition, a protein superfamily can include moonlighting proteins, which perform two or more functions, and pseudoenzymes, which have a three‐dimensional fold that resembles a conventional catalytically active enzyme, but do not have catalytic activity. I will discuss several examples of protein families that contain enzymes with noncanonical catalytic functions, pseudoenzymes, and/or moonlighting proteins. Pseudoenzymes and moonlighting proteins are widespread in the evolutionary tree and are found in many protein families, and they are often very similar in sequence and structure to their monofunctional and catalytically active counterparts. A greater understanding is needed to clarify when similarities and differences in amino acid sequences and structures correspond to similarities and differences in biochemical functions and cellular roles. This information can help improve programs that identify protein functions from sequence or structure and assist in more accurate annotation of sequence and structural databases, as well as in our understanding of the broad diversity of protein functions.