PSAE-2 (photosystem I subunit E-2); catalytic. Identical to Photosystem I reaction center subunit IV B, chloroplast precursor (PSAE2) [Arabidopsis Thaliana] (GB:Q9S714); similar to PSAE-1 (PSA E1 KNOCKOUT), catalytic [Arabidopsis thaliana] (TAIR:AT4G28750.1); similar to PSI reaction center subunit III [Citrus sinensis] (GB:BAF80474.1); contains InterPro domain Electron transport accessory protein; (InterPro:IPR008990); contains InterPro domain Photosystem I reaction centre subunit IV/PsaE; (InterPro:IPR003375)