= Daniel A. Pomeranz Krummel
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\b[Daniel A. Pomeranz Krummel] contributed to determining the architecture of <U1 snRNP>, a <small nuclear ribonucleoprotein> involved in recognizing a <splice site> during <RNA splicing>. He is a joint first author of the 2009 <X-ray crystallography> study of its human functional core.<Crystal structure of human spliceosomal U1 snRNP at 5.5 Å resolution by Daniel A. Pomeranz Krummel and others>[Byline, equal-contribution note and Abstract]{ref}
The investigators reconstituted a particle from <RNA> and <proteins>, collected diffraction at the Swiss Light Source and obtained a 5.5-angstrom <electron density> map. <Heavy-atom labeling> supplied positional landmarks for fitting individual <proteins>, including the seven <Sm proteins>. The crystallized construct omitted the <U1A protein> and used engineered or truncated components; the paper separately modeled the more complete particle.<Crystal structure of human spliceosomal U1 snRNP at 5.5 Å resolution by Daniel A. Pomeranz Krummel and others>[Structure determination; Data Collection; Figures1–5]{ref}
An original counting example clarifies that distinction. Seven <Sm proteins>, two additional U1-specific <proteins> and one <U1 small nuclear RNA> make ten molecular subunits, of which nine are <proteins>. Adding the omitted <U1A protein> gives ten <proteins> plus the <RNA>, rather than ten total subunits. This counts molecular components without asserting that every crystallized polypeptide has its full native sequence.
The scientific value is the spatial organization: a list of component names alone cannot show how <RNA> and <proteins> support one another. Conversely, the arrangement of an engineered functional core must be interpreted with its composition and resolution in view, rather than presented as an unmodified whole <spliceosome>.
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