A carboxypeptidase is a protease enzyme that hydrolyzes (cleaves) a peptide bond at the carboxy-terminal (C-terminal) end of a protein or peptide. This is in contrast to an aminopeptidases, which cleave peptide bonds at the N-terminus of proteins. Humans, animals, bacteria and plants contain several types of carboxypeptidases that have diverse functions ranging from catabolism to protein maturation.(read more DOI: 10.1038/nature06956 and Wikipedia)
This crystal structure belongs to the Neuraminidase such a surprising vegetable.
Neuraminidase is a key protein of influenza viruses and in this structure one inhibitor is also present bound to it. The best-known neuraminidase is the viral neuraminidase, a drug target for the prevention of the spread of influenza infection. The viral neuraminidases are frequently used as antigenic determinants found on the surface of the influenza virus. Some variants of the influenza neuraminidase confer more virulence to the virus than others. The study of neuraminidases and how they evolve, and the research of novel inhibitors are key for having antiviral drugs in the future (read more DOI: 10.1038/nature06956 and Wikipedia)
Sharks have smaller antibodies than usual. IgNAR shows significant structural differences to other antibodies. It has five constant domains (CH) per chain instead of the usual three, several disulfide bonds in unusual positions, and the complementarity-determining region 3 (CDR3) forms an extended loop covering the site which binds to a light chain in other antibodies. These differences, in combination with the phylogenetic age of the cartilaginous fishes, have led to the hypothesis that IgNAR could be more closely related to a primordial antigen-binding protein than the mammalian immunoglobulins. Non-vertebrates do not have antibodies at all. (read more DOI: 10.1073/pnas.1321502111 and Wikipedia)
CcmK4 is a protein forming the shell of protein-only bacterial organelles. these organelles are called microcompartments and are self-assembling (how amazing?) (read more DOI: 10.1021/sb500226j and Wikipedia)