Cytochrome b6f complex - Essay Example

As one of the major photosynthetic protein that is widely been explored in the study of biochemistry, the cytochrome b6f complex is commonly found not only in green algae but also in cyanobacteria (Baniulis et al., 2009; Whitelegge et al., 2002). Each time the plants undergo photosynthesis, the cytochrome b6f complex plays a significant role in the process of transferring the electro-chemical proton ??11 across the thylakoid membrane (Laisk, Nedbal and Govindjee, 2009, p. 159). In other words, the thylakoid membrane in plants is responsible in introducing some protons within the close surroundings of the thylakoid.

As part of analyzing the biochemistry and role of cytochrome b6f complex in the photosynthesis of plants, this study will purposely gather and make use of several scientific-based literature in discussing not only the relationship between the Cytochrome b6f complex and its biochemical structure but also the basic modes of enzyme catalysis in relation to some specific examples. Relationship between Functions of Cytochrome b6f Complex to their Structures To be able to clearly explain the relationship betwen the functions of cytochrome b6f complex and its biochemical structure, it is necessary to first explore the biochemical structure of cytochrome b6f complex followed by discussing the main function of cytochrome b6f complex. . According to Whitelegge et al. (2002), the structure of cytochrome b6f complex is complex due to the fact that cytochrome b6f complex is composed of as much as eight (8) different polypeptide subunits (Baniulis et al.

, 2009; Dashdorj et al., 2005; Genji et al., 2004). In line with this, several studies strongly suggest that cytochrome b6f complex is complex since it is composed of a total of seven (7) prosthetic groups (Baniulis et al., 2008; Cramer et al., 2004). Several studies explained that the structure of cytochrome b6f complex is composed of four large subunits between 17 to 32 kDa such as the membrane bound c-type cytochrome f (PetA), cytochrome b6 (PetB), the Rieske iron-sulfur protein which is also known as the Rieske ISP (PetC), and the subunit IV (PetD) (Baniulus et al.

, 2011; Cramer, Hasan and Yamashita, 2011; Yan and Cramer, 2003; Schneider et al., 2002; Whitelegge et al., 2002). According to Baniulus et al. (2011), petA, petB, petC, and petD are classified as large subunits that can interact well with the redox-active prosthetic groups. Serving as the “picket fence” type of structure that surrounds the core of cytochrome b6f complex’s four (4) larger subunits, the structure of cytochrome b6f complex is also composed of four (4) other hydrophobic subunits (3.2 to 4.2 kDa) which include the PetG, PetL, PetM, and PetN (Baniulus et al.

, 2011; Whitelegge et al., 2002). For example, Kugler et al. (1998) mentioned that the chloroplast cytochrome b6f complex is composed of seven (7) different subunits including very small proteins such as PetG, PetL, and PetM proteins. After conducting an ex-ray structure analysis, Genji et al. (2004) found out that the biochemical structure of cytochrome b6f complex in blue-green algae is crystal in form. Because of