17 kDa polypeptide petD Cytochrome b6-f complex subunit 4 PETD_HORVU 160 MGVTKKPDLNDPVLRAKLAKGMGHNYYGEPAWPNDLLYIFPVVILGTIACNVGLAVLEPSMIGEPADPFATPLEILPEWYFFPVFQILRTVPNKLLGVLLMVSVPTGLLTVPFLENVNKFQNPFRRPVATTVFLIGTVVALWLGIGATLPIDKSLTLGLF Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions (By similarity).