Figure 5. Organization of retroviral Gag, Pro, and Pol proteins.

Figure 5

Organization of retroviral Gag, Pro, and Pol proteins. All Gag proteins contain poorly conserved MA, CA, and NC sequences and differ further in the number and positions of numerous other cleavage products, as shown. Translation past the 3′end of the Gag-coding sequence results in the synthesis of Gag-Pro-Pol fusion proteins. This occurs by either ribosome frameshifting (fs) or in-frame suppression of a stop codon (is). Note the special case of spumaviruses, where there is little processing and Pro-Pol is expressed from a spliced mRNA. The number of amino acids contained within the Gag and Gag-Pro-Pol proteins (Gag and Pro-Pol in the case of HFV) is indicated at the end of each molecule. Myristate is represented by the wavy lines. (SP) Spacer peptide; (TF) transframe protein; (DU) dUTPase; (PPPY) a proline-rich sequence required later in budding; (MHR) the major homology region of CA.

From: Overview of Retroviral Assembly

Cover of Retroviruses
Coffin JM, Hughes SH, Varmus HE, editors.
Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press; 1997.
Copyright © 1997, Cold Spring Harbor Laboratory Press.

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