蛋白酶體是一種多催化蛋白酶復合物，具有高度有序的環狀20S核結構。核心結構由4個28個不相同亞單位的環組成，2個環由7個α亞單位組成，2個環由7個β亞單位組成。蛋白酶體以高濃度分布于真核細胞，并在非溶酶體途徑的ATP/泛素依賴過程中分裂肽。經修飾的蛋白酶體免疫蛋白酶體的一個基本功能是加工I類mhc肽。這個基因編碼蛋白酶體B型家族的一個成員，也被稱為t1b家族，是一個20s核心β亞單位。該基因位于MHC（主要組織相容性復合體）的Ⅱ類區域。該基因的表達由γ干擾素誘導，該基因產物取代了免疫蛋白酶體中的催化亞單位3（蛋白酶體β5亞單位）。蛋白水解過程需要產生一個成熟的亞單位。已經鑒定出兩種編碼兩種亞型的選擇性轉錄物；兩種亞型都經過處理以產生相同的成熟亞基。
The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. This gene encodes a member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. This gene is located in the class II region of the MHC (major histocompatibility complex). Expression of this gene is induced by gamma interferon and this gene product replaces catalytic subunit 3 (proteasome beta 5 subunit) in the immunoproteasome. Proteolytic processing is required to generate a mature subunit. Two alternative transcripts encoding two isoforms have been identified; both isoforms are processed to yield the same mature subunit.