| Primary Identifier | IPR004815 | Type | Family |
| Short Name | Lon_bac/euk-typ |
| description | Lon protease belongs to the S16 peptidase family and is an ATP-dependent serine protease that mediates the selective degradation of mutant and abnormal proteins, as well as certain short-lived regulatory proteins. It is required for cellular homeostasis and for survival from DNA damage and developmental changes induced by stress []. In pathogenic bacteria, it is required for the expression of virulence genes that promote cell infection [].Lon (La) protease was the first ATP-dependent protease to be purified fromE. coli [, , , ]. The enzyme is a homotetramer of 87kDa subunits, with one proteolytic and one ATP-binding site per monomer, making it structurally less complex than other known ATP-dependent proteases []. Despite this relative structural simplicity, Lon recognises its substrates directly, without delegating the task of substrate recognition to other enzymes []. This signature defines the bacterial and eukaryotic lon proteases. This family of sequences does not include the archaeal lon homologues, . In the eukaryotes the majority of the proteins are located in the mitochondrial matrix [, ]. The yeast homologue, Pim1, is required for mitochondrial function and is constitutively expressed, but is increased after thermal stress, suggesting that Pim1 may play a role in the heat shock response []. |
