What are the components of nitrogenase enzyme?

Nitrogenase consists of two major protein components, namely, dinitrogenase (MoFe-protein) and dinitrogenase reductase (Feprotein). Both components contain molybdenum (Mo) as well. The iron (Fe) and molybdenum (Mo) in dinitrogenase (MoFe-protein) are contained in a cofactor called MoFe-cofactor or MoFe-co.

Is nitrogenase a Mo Fe protein?

The catalyst for biological N2 reduction is the enzyme nitrogenase. The enzyme is composed of two-component metalloproteins called the iron (Fe) protein (also called dinitrogenase reductase or component II) and the molybdenum-iron (MoFe) protein (also called dinitrogenase or component I) (Figure 1).

What is the role of the Fe protein of nitrogenase?

The Fe protein plays an essential role in nitrogenase catalysis, serving as the obligate electron donor to the MoFe protein. In addition to its catalytic capacity, the Fe protein is also indispensable for the assembly of the complex clusters in the MoFe protein (11).

What are the 3 metals found in Nitrogenases?

Nitrogenase enzymes have evolved complex iron–sulfur (Fe–S) containing cofactors that most commonly contain molybdenum (MoFe, Nif) as a heterometal but also exist as vanadium (VFe, Vnf) and heterometal-independent (Fe-only, Anf) forms.

What is Holoenzyme and Apoenzyme?

1. Holoenzyme refers to the apoenzyme along with cofactor and also becomes catalytically active. Apoenzyme refers to the inactive form of enzyme. 2. Consists of the apoenzyme and several types of cofactors.

What is P cluster?

The P-cluster mediates the electron flow from NifH to NifDK. Bridged between the α- and β-subunits of NifDK, it is located 10 Å below the surface of the protein [4], [5]. Structurally, the P-cluster can be viewed as two [Fe4S3] partial cubanes bridged by a μ6-sulfide in between (Fig. 2A and B).

What protects nitrogenase?

Nitrogenase is able to reduce acetylene, but is inhibited by carbon monoxide, which binds to the enzyme and thereby prevents binding of dinitrogen. This requires mechanisms for nitrogen fixers to protect nitrogenase from oxygen in vivo.

What is the process of nitrification?

Nitrification is a microbial process by which reduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitrate. Ammonia is present in drinking water through either naturally-occurring processes or through ammonia addition during secondary disinfection to form chloramines.

What are examples of apoenzyme?

Apoenzyme Examples Examples of enzymes consisting of apoenzymes and coenzymes are transferases, oxidoreductases, ligases, and isomerases.

What are the components of apoenzyme?

Apoenzyme meaning The protein component of an enzyme, to which the coenzyme attaches to form an active enzyme. The protein component of an enzyme, excluding additional components such as cofactors or inhibitors. The protein component of an enzyme, to which the coenzyme attaches to form an active enzyme.

What is M cluster?

The M-cluster serves as the active site for substrate reduction. Buried within the α-subunit of NifDK, it is located 14 Å away from the P-cluster. Structurally, the M-cluster can be viewed as [Fe4S3] and [MoFe3S3] partial cubanes bridged by three μ2-sulfides in between (Fig. 2C).

What does the enzyme nitrogenase catalyze?

Nitrogenase is a complex, bacterial enzyme that catalyzes the ATP-dependent reduction of dinitrogen (N2) to ammonia (NH3). In its most prevalent form, it consists of two proteins, the catalytic molybdenum-iron protein (MoFeP) and its specific reductase, the iron protein (FeP).

What are the components of the nitrogenase enzyme?

Nitrogenase consists of two major protein components, namely, dinitrogenase (MoFe-protein) and dinitrogenase reductase (Fe-protein). Both components contain molybdenum (Mo) as well. The iron (Fe) and molybdenum (Mo) in dinitrogenase (MoFe-protein) are contained in a cofactor called MoFe-cofactor or MoFe-co.The…

What makes up the metal clusters in nitrogenase?

The metal clusters are the centerpiece of nitrogenase, and are the major attraction on any tour of the structures. PDB entry 1n2c is a good place to start–it contains both the MoFe protein (in blue and purple at the center) and two copies of the Fe protein dimer bound on either end (shown in green).

What causes a conformational change in the nitrogenase complex?

The hydrolysis of ATP also causes a conformational change within the nitrogenase complex, bringing the Fe protein and MoFe protein closer together for easier electron transfer. The MoFe protein is a heterotetramer consisting of two α subunits and two β subunits, with a mass of approximately 240-250kDa.

How does nitrogenase fix nitrogen in the atmosphere?

Nitrogenase uses an exotic cluster of metals to fix atmospheric nitrogen into bioavailable ammonia. Nitrogenase, with Fe proteins in green and MoFe proteins in blue and magenta.